8351138561204253360128
8,351,138,561,204,253,360,128 is an even composite number composed of four prime numbers multiplied together.
What does the number 8351138561204253360128 look like?
This visualization shows the relationship between its 4 prime factors (large circles) and 1620 divisors.
8351138561204253360128 is an even composite number. It is composed of four distinct prime numbers multiplied together. It has a total of one thousand, six hundred twenty divisors.
Prime factorization of 8351138561204253360128:
219 × 112 × 238 × 412
(2 × 2 × 2 × 2 × 2 × 2 × 2 × 2 × 2 × 2 × 2 × 2 × 2 × 2 × 2 × 2 × 2 × 2 × 2 × 11 × 11 × 23 × 23 × 23 × 23 × 23 × 23 × 23 × 23 × 41 × 41)See below for interesting mathematical facts about the number 8351138561204253360128 from the Numbermatics database.
Names of 8351138561204253360128
- Cardinal: 8351138561204253360128 can be written as Eight sextillion, three hundred fifty-one quintillion, one hundred thirty-eight quadrillion, five hundred sixty-one trillion, two hundred four billion, two hundred fifty-three million, three hundred sixty thousand, one hundred twenty-eight.
Scientific notation
- Scientific notation: 8.351138561204253360128 × 1021
Factors of 8351138561204253360128
Divisors of 8351138561204253360128
- Number of divisors d(n): 1620
-
Complete list of divisors:
1 2 4 8 11 16 22 23 32 41 44 46 64 82 88 92 121 128 164 176 184 242 253 256 328 352 368 451 484 506 512 529 656 704 736 902 943 968 1012 1024 1058 1312 1408 1472 1681 1804 1886 1936 2024 2048 2116 2624 2783 2816 2944 3362 3608 3772 3872 4048 4096 4232 4961 5248 5566 5632 5819 5888 6724 7216 7544 7744 8096 8192 8464 9922 10373 10496 11132 11264 11638 11776 12167 13448 14432 15088 15488 16192 16384 16928 18491 19844 20746 20992 21689 22264 22528 23276 23552 24334 26896 28864 30176 30976 32384 32768 33856 36982 38663 39688 41492 41984 43378 44528 45056 46552 47104 48668 53792 57728 60352 61952 64009 64768 65536 67712 73964 77326 79376 82984 83968 86756 89056 90112 93104 94208 97336 107584 114103 115456 120704 123904 128018 129536 131072 133837 135424 147928 154652 158752 165968 167936 173512 178112 180224 186208 188416 194672 203401 215168 228206 230912 238579 241408 247808 256036 259072 262144 267674 270848 279841 295856 309304 317504 331936 335872 347024 356224 360448 372416 376832 389344 406802 425293 430336 456412 461824 477158 482816 495616 498847 512072 518144 524288 535348 541696 559682 591712 618608 635008 663872 671744 694048 712448 720896 744832 753664 778688 813604 850586 860672 889249 912824 923648 954316 965632 991232 997694 1024144 1036288 1070696 1083392 1119364 1183424 1237216 1270016 1327744 1343488 1388096 1424896 1441792 1472207 1489664 1507328 1557376 1627208 1701172 1721344 1778498 1825648 1847296 1908632 1931264 1982464 1995388 2048288 2072576 2141392 2166784 2238728 2366848 2474432 2540032 2624369 2655488 2686976 2776192 2849792 2883584 2944414 2979328 3014656 3078251 3114752 3254416 3402344 3442688 3556996 3651296 3694592 3817264 3862528 3964928 3990776 4096576 4145152 4282784 4333568 4477456 4678223 4733696 4948864 5080064 5248738 5310976 5373952 5487317 5552384 5699584 5767168 5888828 5958656 6029312 6156502 6229504 6436343 6508832 6804688 6885376 7113992 7302592 7389184 7634528 7725056 7929856 7981552 8193152 8290304 8565568 8667136 8954912 9356446 9467392 9781739 9897728 10160128 10497476 10621952 10747904 10974634 11104768 11399168 11473481 11777656 11917312 12058624 12313004 12459008 12872686 13017664 13609376 13770752 14227984 14605184 14778368 15269056 15450112 15859712 15963104 16386304 16580608 17131136 17334272 17909824 18712892 18934784 19563478 19795456 20320256 20452727 20994952 21243904 21495808 21949268 22209536 22798336 22946962 23555312 23834624 24626008 24918016 25745372 26035328 27218752 27541504 28455968 29210368 29556736 30538112 30900224 31719424 31926208 32772608 33161216 33860761 34262272 34668544 35819648 37425784 37869568 39126956 39590912 40640512 40905454 41989904 42487808 43898536 44419072 45596672 45893924 47110624 47669248 49252016 49836032 51490744 52070656 54437504 55083008 56911936 58420736 59113472 60360487 61076224 61800448 63438848 63852416 65545216 66322432 67721522 68524544 69337088 70799773 71639296 74851568 75739136 78253912 79181824 81281024 81810908 83979808 84975616 87797072 88838144 91193344 91787848 94221248 95338496 98504032 99672064 102981488 104141312 107599129 108875008 110166016 113823872 116841472 118226944 120720974 122152448 123600896 126208291 127704832 131090432 132644864 135443044 137049088 138674176 141599546 143278592 148035889 149703136 151478272 156507824 158363648 162562048 163621816 167959616 169951232 175594144 177676288 182386688 183575696 188442496 190676992 197008064 199344128 205962976 208282624 215198258 217750016 220332032 224979997 227647744 233682944 236453888 241441948 244304896 247201792 252416582 255409664 262180864 263890063 270886088 274098176 277348352 283199092 286557184 296071778 299406272 302956544 313015648 316727296 325124096 327243632 335919232 339902464 351188288 355352576 364773376 367151392 376884992 381353984 394016128 398688256 411925952 416565248 430396516 435500032 440664064 449959994 455295488 467365888 470412721 482883896 488609792 494403584 504833164 510819328 524361728 527780126 541772176 548196352 566398184 573114368 592143556 598812544 605913088 626031296 633454592 650248192 654487264 671838464 679804928 702376576 710705152 729546752 734302784 753769984 762707968 778797503 788032256 797376512 823851904 833130496 860793032 871000064 881328128 899919988 910590976 934731776 940825442 965767792 977219584 1009666328 1021638656 1048723456 1055560252 1083544352 1096392704 1132796368 1146228736 1184287112 1197625088 1211826176 1252062592 1266909184 1300496384 1308974528 1343676928 1359609856 1388291201 1404753152 1421410304 1459093504 1468605568 1507539968 1525415936 1557595006 1576064512 1594753024 1628394779 1647703808 1666260992 1721586064 1742000128 1799839976 1821181952 1869463552 1881650884 1931535584 1954439168 2019332656 2043277312 2097446912 2111120504 2167088704 2192785408 2265592736 2292457472 2368574224 2395250176 2423652352 2474779967 2504125184 2533818368 2600992768 2617949056 2687353856 2719219712 2776582402 2809506304 2842820608 2902790693 2937211136 3015079936 3050831872 3115190012 3152129024 3189506048 3256789558 3295407616 3332521984 3404825447 3443172128 3484000256 3599679952 3642363904 3738927104 3763301768 3863071168 3908878336 4038665312 4086554624 4194893824 4222241008 4334177408 4385570816 4531185472 4584914944 4737148448 4790500352 4847304704 4949559934 5008250368 5067636736 5174539931 5235898112 5374707712 5438439424 5553164804 5619012608 5685641216 5805581386 5874422272 6030159872 6069471449 6230380024 6304258048 6379012096 6513579116 6590815232 6665043968 6809650894 6886344256 6968000512 7199359904 7284727808 7477854208 7526603536 7726142336 7817756672 8077330624 8173109248 8389787648 8444482016 8668354816 8771141632 9062370944 9169829888 9474296896 9581000704 9694609408 9899119868 10016500736 10135273472 10349079862 10471796224 10749415424 10819492583 11106329608 11238025216 11371282432 11611162772 11748844544 12060319744 12138942898 12460760048 12608516096 13027158232 13181630464 13330087936 13619301788 13772688512 13936001024 14398719808 14569455616 14955708416 15053207072 15452284672 15635513344 16154661248 16346218496 16779575296 16888964032 17336709632 17542283264 17912342569 18124741888 18339659776 18948593792 19162001408 19798239736 20033001472 20270546944 20698159724 20943592448 21498830848 21638985166 22212659216 22476050432 23222325544 23497689088 24120639488 24277885796 24921520096 25217032192 26054316464 26363260928 26660175872 27238603576 27545377024 27872002048 28797439616 29138911232 29911416832 30106414144 30904569344 31271026688 31930697623 32309322496 32692436992 33559150592 33777928064 34673419264 35084566528 35824685138 36249483776 36679319552 37453079917 37897187584 38324002816 39596479472 40066002944 41396319448 41887184896 42997661696 43277970332 44425318432 44952100864 46444651088 46995378176 48241278976 48555771592 49843040192 50434064384 52108632928 52726521856 53320351744 54477207152 55090754048 55744004096 56919939241 57594879232 58277822464 59822833664 60212828288 61809138688 62542053376 63861395246 64618644992 65384873984 66764185939 67555856128 69346838528 70169133056 71649370276 72498967552 73358639104 74906159834 75794375168 76648005632 78310985281 79192958944 80132005888 82792638896 83774369792 85995323392 86555940664 88850636864 89904201728 92889302176 93990756352 96482557952 97111543184 99686080384 100868128768 104217265856 105453043712 106640703488 108954414304 110181508096 111488008192 113839878482 115189758464 116555644928 119014418413 120425656576 123618277376 125084106752 127722790492 129237289984 130769747968 133528371878 135111712256 138693677056 139597843327 143298740552 144997935104 146717278208 149812319668 151588750336 153296011264 156621970562 158385917888 160264011776 165585277792 167548739584 171990646784 173111881328 177701273728 179808403456 185778604352 187981512704 192965115904 194223086368 199372160768 201736257536 208434531712 210906087424 217908828608 220363016192 222976016384 227679756964 230379516928 233111289856 238028836826 240851313152 247236554752 248848329409 255445580984 258474579968 261539495936 267056743756 270223424512 277387354112 279195686654 286597481104 289995870208 299624639336 303177500672 306592022528 313243941124 316771835776 320528023552 331170555584 335097479168 343981293568 346223762656 355402547456 359616806912 371557208704 375963025408 385930231808 388446172736 398744321536 403472515072 411983879087 416869063424 421812174848 435817657216 440726032384 455359513928 460759033856 466222579712 476057673652 481702626304 494473109504 497696658818 510891161968 516949159936 534113487512 540446849024 554774708224 558391373308 573194962208 579991740416 599249278672 606355001344 613184045056 626487882248 633543671552 641056047104 662341111168 670194958336 687962587136 692447525312 710805094912 719233613824 734406045329 743114417408 751926050816 771860463616 776892345472 797488643072 806945030144 823967758174 833738126848 843624349696 861420838091 871635314432 881452064768 910719027856 921518067712 952115347304 963405252608 988946219008 995393317636 1021782323936 1033898319872 1068226975024 1080893698048 1109549416448 1116782746616 1146389924416 1159983480832 1198498557344 1212710002688 1226368090112 1252975764496 1267087343104 1282112094208 1309158602543 1324682222336 1340389916672 1375925174272 1384895050624 1421610189824 1438467227648 1468812090658 1486228834816 1503852101632 1535576276597 1553784690944 1594977286144 1613890060288 1647935516348 1667476253696 1687248699392 1722841676182 1743270628864 1762904129536 1821438055712 1843036135424 1904230694608 1926810505216 1977892438016 1990786635272 2043564647872 2067796639744 2136453950048 2161787396096 2219098832896 2233565493232 2292779848832 2319966961664 2396997114688 2425420005376 2452736180224 2505951528992 2534174686208 2564224188416 2618317205086 2649364444672 2680779833344 2737331623499 2769790101248 2843220379648 2876934455296 2937624181316 2972457669632 3007704203264 3071152553194 3107569381888 3189954572288 3210750396521 3295871032696 3334952507392 3374497398784 3445683352364 3486541257728 3525808259072 3642876111424 3686072270848 3808461389216 3853621010432 3955784876032 3981573270544 4087129295744 4135593279488 4272907900096 4323574792192 4438197665792 4467130986464 4585559697664 4639933923328 4793994229376 4850840010752 5011903057984 5068349372416 5128448376832 5236634410172 5298728889344 5361559666688 5474663246998 5539580202496 5686440759296 5723511576407 5875248362632 5944915339264 6015408406528 6142305106388 6215138763776 6379909144576 6421500793042 6591742065392 6669905014784 6891366704728 6973082515456 7051616518144 7285752222848 7372144541696 7616922778432 7707242020864 7911569752064 7963146541088 8174258591488 8271186558976 8545815800192 8647149584384 8876395331584 8934261972928 9171119395328 9279867846656 9475629219001 9587988458752 9701680021504 10023806115968 10136698744832 10473268820344 10597457778688 10723119333376 10949326493996 11079160404992 11372881518592 11447023152814 11750496725264 11889830678528 12284610212776 12430277527552 12759818289152 12843001586084 13183484130784 13339810029568 13782733409456 13946165030912 14103233036288 14571504445696 14744289083392 15233845556864 15414484041728 15823139504128 15926293082176 16348517182976 16542373117952 16891339042567 17091631600384 17294299168768 17752790663168 17868523945856 18342238790656 18559735693312 18951258438002 19175976917504 19403360043008 20047612231936 20273397489664 20946537640688 21194915557376 21898652987992 22158320809984 22745763037184 22894046305628 23500993450528 23779661357056 24569220425552 24860555055104 25519636578304 25686003172168 26366968261568 26679620059136 27565466818912 27892330061824 28206466072576 29143008891392 29488578166784 30110647858489 30467691113728 30828968083456 31646279008256 31852586164352 32697034365952 33084746235904 33782678085134 34183263200768 34588598337536 35318254361731 35737047891712 36684477581312 37119471386624 37902516876004 38351953835008 38806720086016 40095224463872 40546794979328 41893075281376 42389831114752 43797305975984 44316641619968 45491526074368 45788092611256 47001986901056 47559322714112 49138440851104 49721110110208 51039273156608 51372006344336 52733936523136 53359240118272 55130933637824 55784660123648 56412932145152 58286017782784 58977156333568 60221295716978 60935382227456 61657936166912 62958627340477 63705172328704 65394068731904 66169492471808 67565356170268 68366526401536 69177196675072 70636508723462 71474095783424 73368955162624 75805033752008 76703907670016 77613440172032 80190448927744 81093589958656 83786150562752 84779662229504 87594611951968 88633283239936 90983052148736 91576185222512 94003973802112 95118645428224 98276881702208 99442220220416 102078546313216 102744012688672 105467873046272 106718480236544 110261867275648 111569320247296 116572035565568 117954312667136 120442591433956 121870764454912 123315872333824 125917254680954 127410344657408 130788137463808 131640766257361 135130712340536 136733052803072 138354393350144 141273017446924 142948191566848 146737910325248 151610067504016 153407815340032 160380897855488 162187179917312 167572301125504 169559324459008 175189223903936 177266566479872 181966104297472 183152370445024 188007947604224 190237290856448 196553763404416 198884440440832 204157092626432 205488025377344 210935746092544 213436960473088 220523734551296 223138640494592 233144071131136 240885182867912 243741528909824 246631744667648 251834509361908 254820689314816 261576274927616 263281532514722 270261424681072 273466105606144 282546034893848 285896383133696 293475820650496 303220135008032 306815630680064 320761795710976 324374359834624 335144602251008 339118648918016 350378447807872 354533132959744 363932208594944 366304740890048 376015895208448 380474581712896 388500797979041 393107526808832 397768880881664 408314185252864 410976050754688 421871492185088 426873920946176 441047469102592 446277280989184 466288142262272 481770365735824 487483057819648 503669018723816 509641378629632 523152549855232 526563065029444 540522849362144 546932211212288 565092069787696 571792766267392 586951641300992 606440270016064 613631261360128 641523591421952 648748719669248 670289204502016 678237297836032 692544900745247 700756895615744 709066265919488 727864417189888 732609481780096 752031790416896 760949163425792 777001595958082 786215053617664 795537761763328 821952101509376 843742984370176 853747841892352 882094938205184 892554561978368 932576284524544 963540731471648 974966115639296 1007338037447632 1019282757259264 1046305099710464 1053126130058888 1081045698724288 1093864422424576 1130184139575392 1143585532534784 1173903282601984 1212880540032128 1227262522720256 1283047182843904 1297497439338496 1340578409004032 1356474595672064 1385089801490494 1401513791231488 1418132531838976 1448048428830971 1465218963560192 1504063580833792 1521898326851584 1554003191916164 1572430107235328 1591075523526656 1643904203018752 1687485968740352 1764189876410368 1785109123956736 1865152569049088 1927081462943296 1949932231278592 2014676074895264 2038565514518528 2092610199420928 2106252260117776 2162091397448576 2187728844849152 2260368279150784 2287171065069568 2347806565203968 2425761080064256 2454525045440512 2566094365687808 2681156818008064 2712949191344128 2770179602980988 2803027582462976 2836265063677952 2896096857661942 2930437927120384 3008127161667584 3108006383832328 3144860214470656 3182151047053312 3287808406037504 3374971937480704 3528379752820736 3730305138098176 3854162925886592 3899864462557184 4029352149790528 4077131029037056 4185220398841856 4212504520235552 4324182794897152 4375457689698304 4520736558301568 4574342130139136 4695613130407936 4851522160128512 4909050090881024 5132188731375616 5362313636016128 5540359205961976 5606055164925952 5672530127355904 5792193715323884 5860875854240768 6016254323335168 6216012767664656 6289720428941312 6575616812075008 6749943874961408 7056759505641472 7460610276196352 7708325851773184 7799728925114368 8058704299581056 8154262058074112 8370440797683712 8425009040471104 8648365589794304 8750915379396608 9041473116603136 9148684260278272 9391226260815872 9703044320257024 9818100181762048 10264377462751232 10724627272032256 11080718411923952 11212110329851904 11584387430647768 11721751708481536 12032508646670336 12432025535329312 12579440857882624 13151233624150016 13499887749922816 14113519011282944 14921220552392704 15416651703546368 15599457850228736 15928532717140681 16117408599162112 16308524116148224 16740881595367424 16850018080942208 17296731179588608 17501830758793216 18082946233206272 18297368520556544 19406088640514048 19636200363524096 20528754925502464 21449254544064512 22161436823847904 22424220659703808 23168774861295536 23443503416963072 24065017293340672 24864051070658624 25158881715765248 26302467248300032 26999775499845632 28227038022565888 29842441104785408 30833303407092736 31198915700457472 31857065434281362 32234817198324224 32617048232296448 33700036161884416 34593462359177216 35003661517586432 36165892466412544 36594737041113088 38812177281028096 41057509851004928 42898509088129024 44322873647695808 44848441319407616 46337549722591072 46887006833926144 48130034586681344 49728102141317248 50317763431530496 52604934496600064 53999550999691264 56454076045131776 61666606814185472 62397831400914944 63714130868562724 64469634396648448 65234096464592896 67400072323768832 69186924718354432 72331784932825088 73189474082226176 77624354562056192 85797018176258048 88645747295391616 89696882638815232 92675099445182144 93774013667852288 96260069173362688 99456204282634496 100635526863060992 105209868993200128 107999101999382528 112908152090263552 123333213628370944 127428261737125448 128939268793296896 130468192929185792 134800144647537664 138373849436708864 144663569865650176 155248709124112384 171594036352516096 177291494590783232 179393765277630464 185350198890364288 187548027335704576 192520138346725376 198912408565268992 201271053726121984 210419737986400256 215998203998765056 225816304180527104 246666427256741888 254856523474250896 257878537586593792 269600289295075328 276747698873417728 289327139731300352 310497418248224768 343188072705032192 354582989181566464 358787530555260928 370700397780728576 375096054671409152 385040276693450752 397824817130537984 402542107452243968 420839475972800512 451632608361054208 493332854513483776 509713046948501792 515757075173187584 539200578590150656 553495397746835456 578654279462600704 620994836496449536 686376145410064384 709165978363132928 717575061110521856 741400795561457152 750192109342818304 795649634261075968 805084214904487936 841678951945601024 986665709026967552 1019426093897003584 1031514150346375168 1078401157180301312 1106990795493670912 1157308558925201408 1241989672992899072 1418331956726265856 1435150122221043712 1482801591122914304 1500384218685636608 1591299268522151936 1683357903891202048 1973331418053935104 2038852187794007168 2063028300692750336 2156802314360602624 2213981590987341824 2314617117850402816 2483979345985798144 2836663913452531712 2965603182245828608 3000768437371273216 3182598537044303872 3946662836107870208 4077704375588014336 4126056601385500672 4313604628721205248 4427963181974683648 4629234235700805632 4967958691971596288 5673327826905063424 5931206364491657216 6365197074088607744 7893325672215740416 8155408751176028672 8252113202771001344 8627209257442410496 8855926363949367296 9258468471401611264 11346655653810126848 11862412728983314432 12730394148177215488 15786651344431480832 16310817502352057344 16504226405542002688 17254418514884820992 18516936942803222528 22693311307620253696 23724825457966628864 25460788296354430976 32621635004704114688 33008452811084005376 34508837029769641984 45386622615240507392 47449650915933257728 50921576592708861952 65243270009408229376 69017674059539283968 90773245230481014784 94899301831866515456 101843153185417723904 130486540018816458752 181546490460962029568 189798603663733030912 203686306370835447808 260973080037632917504 363092980921924059136 379597207327466061824 521946160075265835008 759194414654932123648 1043892320150531670016 2087784640301063340032 4175569280602126680064 8351138561204253360128
- Sum of all divisors σ(n): 19672713211225141954425
- Sum of proper divisors (its aliquot sum) s(n): 11321574650020888594297
- 8351138561204253360128 is an abundant number, because the sum of its proper divisors (11321574650020888594297) is greater than itself. Its abundance is 2970436088816635234169
Bases of 8351138561204253360128
- Binary: 11100010010110111010101000011001100101111110101100100100000000000000000002
- Hexadecimal: 0x1C4B754332FD6480000
- Base-36: 1CYG1A8J1YTZCOW
Squares and roots of 8351138561204253360128
- 8351138561204253360128 squared (83511385612042533601282) is 69741515268432646944999240826739578460176384
- 8351138561204253360128 cubed (83511385612042533601283) is 582421057475023082767677590210479622528934642855240742667552817152
-
The
square root of 8351138561204253360128 is 91384564129.8586780107 -
The
cube root of 8351138561204253360128 is 20288435.7126086829
Scales and comparisons
How big is 8351138561204253360128?- 8,351,138,561,204,253,360,128 seconds is equal to 293,274,701,009 years, 3 weeks, 3 days, 15 hours, 30 minutes, 7 seconds.
-
To count from 1 to 8,351,138,561,204,253,360,128 would take you about two hundred ninety-three billion, two hundred seventy-four million, seven hundred one thousand and nine years!
This is a very rough estimate, based on a speaking rate of half a second every third order of magnitude. If you speak quickly, you could probably say any randomly-chosen number between one and a thousand in around half a second. Very big numbers obviously take longer to say, so we add half a second for every extra x1000. (We do not count involuntary pauses, bathroom breaks or the necessity of sleep in our calculation!)
- A cube with a volume of 8351138561204253360128 cubic inches would be around 1690703 feet tall.
Recreational maths with 8351138561204253360128
- 8351138561204253360128 backwards is 8210633524021658311538
- The number of decimal digits it has is: 22
- The sum of 8351138561204253360128's digits is 77
- More coming soon!
Link to this page
HTML: To link to this page, just copy and paste the link below into your blog, web page or email.
BBCODE: To link to this page in a forum post or comment box, just copy and paste the link code below:
Cite this page
MLA style:
"Number 8351138561204253360128 - Facts about the integer". Numbermatics.com. 2024. Web. 19 June 2024.
APA style:
Numbermatics. (2024). Number 8351138561204253360128 - Facts about the integer. Retrieved 19 June 2024, from https://numbermatics.com/n/8351138561204253360128/
Chicago style:
Numbermatics. 2024. "Number 8351138561204253360128 - Facts about the integer". https://numbermatics.com/n/8351138561204253360128/
The information we have on file for 8351138561204253360128 includes mathematical data and numerical statistics calculated using standard algorithms and methods. We are adding more all the time. If there are any features you would like to see, please contact us. Information provided for educational use, intellectual curiosity and fun!
Keywords: Divisors of 8351138561204253360128, math, Factors of 8351138561204253360128, curriculum, school, college, exams, university, Prime factorization of 8351138561204253360128, STEM, science, technology, engineering, physics, economics, calculator, eight sextillion, three hundred fifty-one quintillion, one hundred thirty-eight quadrillion, five hundred sixty-one trillion, two hundred four billion, two hundred fifty-three million, three hundred sixty thousand, one hundred twenty-eight.