1321658841162313728
1,321,658,841,162,313,728 is an even composite number composed of four prime numbers multiplied together.
1321658841162313728 is an even composite number. It is composed of four distinct prime numbers multiplied together. It has a total of one thousand, eight hundred seventy-two divisors.
Prime factorization of 1321658841162313728:
212 × 311 × 235 × 283
(2 × 2 × 2 × 2 × 2 × 2 × 2 × 2 × 2 × 2 × 2 × 2 × 3 × 3 × 3 × 3 × 3 × 3 × 3 × 3 × 3 × 3 × 3 × 23 × 23 × 23 × 23 × 23 × 283)See below for interesting mathematical facts about the number 1321658841162313728 from the Numbermatics database.
Names of 1321658841162313728
- Cardinal: 1321658841162313728 can be written as One quintillion, three hundred twenty-one quadrillion, six hundred fifty-eight trillion, eight hundred forty-one billion, one hundred sixty-two million, three hundred thirteen thousand, seven hundred twenty-eight.
Scientific notation
- Scientific notation: 1.321658841162313728 × 1018
Factors of 1321658841162313728
Divisors of 1321658841162313728
- Number of divisors d(n): 1872
-
Complete list of divisors:
1 2 3 4 6 8 9 12 16 18 23 24 27 32 36 46 48 54 64 69 72 81 92 96 108 128 138 144 162 184 192 207 216 243 256 276 283 288 324 368 384 414 432 486 512 529 552 566 576 621 648 729 736 768 828 849 864 972 1024 1058 1104 1132 1152 1242 1296 1458 1472 1536 1587 1656 1698 1728 1863 1944 2048 2116 2187 2208 2264 2304 2484 2547 2592 2916 2944 3072 3174 3312 3396 3456 3726 3888 4096 4232 4374 4416 4528 4608 4761 4968 5094 5184 5589 5832 5888 6144 6348 6509 6561 6624 6792 6912 7452 7641 7776 8464 8748 8832 9056 9216 9522 9936 10188 10368 11178 11664 11776 12167 12288 12696 13018 13122 13248 13584 13824 14283 14904 15282 15552 16767 16928 17496 17664 18112 18432 19044 19527 19683 19872 20376 20736 22356 22923 23328 23552 24334 25392 26036 26244 26496 27168 27648 28566 29808 30564 31104 33534 33856 34992 35328 36224 36501 36864 38088 39054 39366 39744 40752 41472 42849 44712 45846 46656 47104 48668 50301 50784 52072 52488 52992 54336 55296 57132 58581 59049 59616 61128 62208 67068 67712 68769 69984 70656 72448 73002 76176 78108 78732 79488 81504 82944 85698 89424 91692 93312 94208 97336 100602 101568 104144 104976 105984 108672 109503 110592 114264 117162 118098 119232 122256 124416 128547 134136 135424 137538 139968 141312 144896 146004 149707 150903 152352 156216 157464 158976 163008 165888 171396 175743 177147 178848 183384 186624 194672 201204 203136 206307 208288 209952 211968 217344 219006 228528 234324 236196 238464 244512 248832 257094 268272 270848 275076 279841 279936 282624 289792 292008 299414 301806 304704 312432 314928 317952 326016 328509 331776 342792 351486 354294 357696 366768 373248 385641 389344 402408 406272 412614 416576 419904 423936 434688 438012 449121 452709 457056 468648 472392 476928 489024 497664 514188 527229 536544 541696 550152 559682 559872 579584 584016 598828 603612 609408 618921 624864 629856 635904 652032 657018 685584 702972 708588 715392 733536 746496 771282 778688 804816 812544 825228 833152 839523 839808 847872 869376 876024 898242 905418 914112 937296 944784 953856 978048 985527 995328 1028376 1054458 1073088 1083392 1100304 1119364 1119744 1156923 1159168 1168032 1197656 1207224 1218816 1237842 1249728 1259712 1271808 1304064 1314036 1347363 1358127 1371168 1405944 1417176 1430784 1467072 1492992 1542564 1557376 1581687 1609632 1625088 1650456 1666304 1679046 1679616 1738752 1752048 1796484 1810836 1828224 1856763 1874592 1889568 1907712 1956096 1971054 2056752 2108916 2146176 2166784 2200608 2238728 2239488 2313846 2336064 2395312 2414448 2437632 2475684 2499456 2518569 2519424 2543616 2608128 2628072 2694726 2716254 2742336 2811888 2834352 2861568 2934144 2956581 2985984 3085128 3114752 3163374 3219264 3250176 3300912 3332608 3358092 3359232 3443261 3470769 3477504 3504096 3592968 3621672 3656448 3713526 3749184 3779136 3815424 3912192 3942108 4042089 4074381 4113504 4217832 4292352 4401216 4477456 4478976 4627692 4672128 4745061 4790624 4828896 4875264 4951368 4998912 5037138 5038848 5216256 5256144 5389452 5432508 5484672 5570289 5623776 5668704 5723136 5868288 5913162 6170256 6229504 6326748 6436343 6438528 6500352 6601824 6665216 6716184 6718464 6886522 6941538 7008192 7185936 7243344 7312896 7427052 7498368 7555707 7558272 7630848 7824384 7884216 8084178 8148762 8227008 8435664 8584704 8802432 8869743 8954912 8957952 9255384 9344256 9490122 9581248 9657792 9750528 9902736 9997824 10074276 10077696 10329783 10412307 10432512 10512288 10778904 10865016 10969344 11140578 11247552 11337408 11446272 11736576 11826324 12126267 12340512 12459008 12653496 12872686 12877056 13203648 13330432 13432368 13436928 13773044 13883076 14016384 14235183 14371872 14486688 14625792 14854104 14996736 15111414 15116544 15648768 15768432 16168356 16297524 16454016 16710867 16871328 17169408 17604864 17739486 17909824 18510768 18688512 18980244 19162496 19309029 19315584 19501056 19805472 19995648 20148552 20155392 20659566 20824614 21024576 21557808 21730032 21938688 22281156 22495104 22667121 22674816 22892544 23473152 23652648 24252534 24681024 24918016 25306992 25745372 25754112 26407296 26609229 26660864 26864736 26873856 27546088 27766152 28032768 28470366 28743744 28973376 29251584 29708208 29993472 30222828 30233088 30989349 31236921 31297536 31536864 32336712 32595048 32908032 33421734 33742656 34338816 35209728 35478972 35819648 36378801 37021536 37377024 37960488 38324992 38618058 38631168 39610944 39991296 40297104 40310784 41319132 41649228 42049152 42705549 43115616 43460064 43877376 44562312 44990208 45334242 45349632 46946304 47305296 48505068 49362048 49836032 50132601 50613984 51490744 51508224 52814592 53218458 53729472 55092176 55532304 56065536 56940732 57487488 57927087 57946752 58503168 59416416 59986944 60445656 60466176 61978698 62473842 63073728 64673424 65190096 65816064 66843468 67485312 68001363 68677632 70419456 70957944 71639296 72757602 74043072 74754048 75920976 76649984 77236116 77262336 79195003 79221888 79827687 79982592 80594208 80621568 82638264 83298456 84098304 85411098 86231232 86920128 87754752 89124624 89980416 90668484 90699264 92968047 93710763 93892608 94610592 97010136 98724096 100265202 101227968 102981488 103016448 105629184 106436916 107458944 109136403 110184352 111064608 112131072 113881464 114974976 115854174 115893504 118832832 119973888 120891312 120932352 123957396 124947684 126147456 128116647 129346848 130380192 131632128 133686936 134970624 136002726 140838912 141915888 143278592 145515204 148086144 149508096 151841952 153299968 154472232 154524672 158390006 158443776 159655374 161188416 165276528 166596912 168196608 170822196 172462464 173781261 173840256 175509504 178249248 179960832 181336968 181398528 185936094 187421526 189221184 194020272 197448192 200530404 202455936 204004089 205962976 206032896 211258368 212873832 214917888 218272806 220368704 222129216 224262144 227762928 229949952 231708348 231787008 237585009 237665664 239483061 239947776 241782624 241864704 247914792 249895368 252294912 256233294 258693696 260760384 263264256 267373872 269941248 272005452 278904141 281677824 283831776 286557184 291030408 296172288 303683904 306599936 308944464 309049344 316780012 316887552 319310748 322376832 327409209 330553056 333193824 336393216 341644392 344924928 347562522 347680512 356498496 359921664 362673936 362797056 371872188 374843052 378442368 384349941 388040544 394896384 401060808 404911872 408008178 411925952 422516736 425747664 429835776 436545612 440737408 444258432 448524288 455525856 459899904 463416696 463574016 475170018 475331328 478966122 483565248 495829584 499790736 504589824 512466588 517387392 521343783 521520768 526528512 534747744 539882496 544010904 557808282 567663552 573114368 582060816 592344576 607367808 612012267 613199872 617888928 618098688 633560024 633775104 638621496 644753664 654818418 661106112 666387648 672786432 683288784 689849856 695125044 695361024 712755027 712996992 718449183 719843328 725347872 725594112 743744376 749686104 756884736 768699882 776081088 789792768 802121616 809823744 816016356 823851904 836712423 845033472 851495328 859671552 873091224 881474816 888516864 911051712 919799808 926833392 927148032 950340036 950662656 957932244 967130496 982227627 991659168 999581472 1009179648 1024933176 1034774784 1042687566 1043041536 1069495488 1079764992 1088021808 1115616564 1135327104 1146228736 1153049823 1164121632 1184689152 1214735616 1224024534 1235777856 1267120048 1267550208 1277242992 1289507328 1309636836 1322212224 1332775296 1345572864 1366577568 1379699712 1390250088 1390722048 1425510054 1425993984 1436898366 1450695744 1487488752 1499372208 1513769472 1537399764 1552162176 1564031349 1579585536 1604243232 1619647488 1632032712 1647703808 1673424846 1702990656 1719343104 1746182448 1762949632 1777033728 1821485069 1822103424 1836036801 1839599616 1853666784 1854296064 1900680072 1901325312 1915864488 1934260992 1964455254 1983318336 1999162944 2018359296 2049866352 2069549568 2085375132 2086083072 2138265081 2138990976 2155347549 2159529984 2176043616 2231233128 2270654208 2306099646 2328243264 2369378304 2429471232 2448049068 2471555712 2510137269 2534240096 2535100416 2554485984 2579014656 2619273672 2644424448 2665550592 2733155136 2759399424 2780500176 2781444096 2851020108 2851987968 2873796732 2901391488 2946682881 2974977504 2998744416 3027538944 3074799528 3104324352 3128062698 3208486464 3239294976 3264065424 3295407616 3346849692 3405981312 3438686208 3492364896 3525899264 3554067456 3642970138 3644206848 3672073602 3707333568 3801360144 3802650624 3831728976 3868521984 3928910508 3966636672 3998325888 4036718592 4099732704 4139099136 4170750264 4172166144 4276530162 4277981952 4310695098 4352087232 4462466256 4541308416 4612199292 4656486528 4692094047 4738756608 4858942464 4896098136 4943111424 5020274538 5068480192 5108971968 5158029312 5238547344 5288848896 5331101184 5464455207 5466310272 5508110403 5518798848 5561000352 5562888192 5702040216 5703975936 5747593464 5802782976 5893365762 5949955008 5997488832 6055077888 6149599056 6208648704 6256125396 6414795243 6416972928 6478589952 6528130848 6590815232 6693699384 6811962624 6984729792 7051798528 7108134912 7285940276 7288413696 7344147204 7414667136 7530411807 7602720288 7605301248 7663457952 7737043968 7857821016 7933273344 7996651776 8199465408 8278198272 8341500528 8344332288 8553060324 8555963904 8621390196 8704174464 8840048643 8924932512 9082616832 9224398584 9312973056 9384188094 9717884928 9792196272 9886222848 10040549076 10136960384 10217943936 10316058624 10477094688 10577697792 10662202368 10928910414 10932620544 11016220806 11122000704 11404080432 11407951872 11495186928 11605565952 11786731524 11899910016 11994977664 12110155776 12299198112 12417297408 12512250792 12829590486 12833945856 13056261696 13181630464 13387398768 13623925248 13969459584 14076282141 14103597056 14216269824 14571880552 14576827392 14688294408 14829334272 15060823614 15205440576 15326915904 15474087936 15715642032 15866546688 15993303552 16393365621 16398930816 16524331209 16556396544 16683001056 16688664576 17106120648 17111927808 17242780392 17408348928 17680097286 17849865024 18165233664 18448797168 18625946112 18768376188 19244385729 19435769856 19584392544 19772445696 20081098152 20273920768 20435887872 20954189376 21155395584 21324404736 21857820828 21865241088 22032441612 22244001408 22591235421 22808160864 22815903744 22990373856 23211131904 23573463048 23799820032 23989955328 24598396224 24834594816 25024501584 25659180972 25667891712 26112523392 26363260928 26520145929 26774797536 27247850496 27938919168 28152564282 29143761104 29153654784 29376588816 29658668544 30121647228 30410881152 30653831808 30948175872 31431284064 31733093376 31986607104 32786731242 32797861632 33048662418 33366002112 34212241296 34223855616 34485560784 34816697856 35360194572 35699730048 36330467328 36897594336 37251892224 37536752376 38488771458 39168785088 39544891392 40162196304 40547841536 40871775744 41908378752 42228846423 42310791168 42648809472 43715641656 43730482176 44064883224 44488002816 45182470842 45616321728 45980747712 46422263808 47146926096 47599640064 47979910656 49180096863 49196792448 49572993627 49669189632 50049003168 51318361944 51335783424 52225046784 53040291858 53549595072 54495700992 55877838336 56305128564 57733157187 58287522208 58307309568 58753177632 59317337088 60243294456 60821762304 61307663616 62862568128 63466186752 63973214208 65573462484 65595723264 66097324836 66732004224 67773706263 68424482592 68447711232 68971121568 69633395712 70720389144 71399460096 73795188672 74503784448 75073504752 76977542916 78337570176 79089782784 80324392608 81095683072 81743551488 83816757504 84457692846 87431283312 87460964352 88129766448 88976005632 90364941684 91232643456 91961495424 92844527616 94293852192 95199280128 95959821312 98360193726 98393584896 99145987254 100098006336 102636723888 102671566848 104450093568 106080583716 107099190144 108991401984 111755676672 112610257128 115466314374 116575044416 117506355264 118634674176 120486588912 121643524608 122615327232 125725136256 126686539269 126932373504 127946428416 131146924968 131191446528 132194649672 133464008448 135547412526 136848965184 137942243136 139266791424 141440778288 142798920192 147540290589 147590377344 149007568896 150147009504 153955085832 156675140352 160648785216 162191366144 163487102976 167633515008 168915385692 173199471561 174862566624 174921928704 176259532896 177952011264 180729883368 182465286912 183922990848 188587704384 190398560256 191919642624 196720387452 196787169792 198291974508 200196012672 203321118789 205273447776 205343133696 208900187136 212161167432 214198380288 223511353344 225220514256 230932628748 233150088832 235012710528 237269348352 240973177824 243287049216 245230654464 251450272512 253373078538 262293849936 262382893056 264389299344 266928016896 271094825052 273697930368 275884486272 278533582848 282881556576 285597840384 295080581178 295180754688 300294019008 307910171664 313350280704 321297570432 324382732288 326974205952 335267030016 337830771384 346398943122 349725133248 352519065792 355904022528 361459766736 364930573824 367845981696 377175408768 380059617807 380797120512 383839285248 393440774904 393574339584 396583949016 400392025344 406642237578 410546895552 417800374272 424322334864 428396760576 442620871767 447022706688 450441028512 461865257496 466300177664 470025421056 481946355648 486574098432 490461308928 502900545024 506746157076 519598414683 524587699872 524765786112 528778598688 533856033792 542189650104 547395860736 551768972544 565763113152 571195680768 590161162356 590361509376 600588038016 609963356367 615820343328 626700561408 642595140864 670534060032 675661542768 692797886244 699450266496 705038131584 711808045056 722919533472 729861147648 735691963392 754350817536 760119235614 786881549808 787148679168 793167898032 800784050688 813284475156 821093791104 835600748544 848644669728 856793521152 885241743534 900882057024 923730514992 932600355328 940050842112 963892711296 973148196864 980922617856 1005801090048 1013492314152 1039196829366 1049175399744 1057557197376 1067712067584 1084379300208 1094791721472 1103537945088 1131526226304 1140178853421 1142391361536 1180322324712 1180723018752 1201176076032 1219926712734 1231640686656 1253401122816 1285190281728 1327862615301 1341068120064 1351323085536 1385595772488 1398900532992 1410076263168 1445839066944 1459722295296 1471383926784 1508701635072 1520238471228 1558795244049 1573763099616 1574297358336 1586335796064 1601568101376 1626568950312 1642187582208 1697289339456 1713587042304 1770483487068 1801764114048 1847461029984 1865200710656 1880101684224 1927785422592 2011602180096 2026984628304 2078393658732 2098350799488 2115114394752 2135424135168 2168758600416 2189583442944 2207075890176 2263052452608 2280357706842 2360644649424 2361446037504 2402352152064 2439853425468 2463281373312 2506802245632 2570380563456 2655725230602 2702646171072 2771191544976 2797801065984 2820152526336 2891678133888 2919444590592 2942767853568 3017403270144 3040476942456 3117590488098 3147526199232 3172671592128 3203136202752 3253137900624 3284375164416 3394578678912 3427174084608 3540966974136 3603528228096 3694922059968 3730401421312 3760203368448 3855570845184 3983587845903 4023204360192 4053969256608 4156787317464 4196701598976 4230228789504 4337517200832 4379166885888 4414151780352 4526104905216 4560715413684 4676385732147 4721289298848 4722892075008 4804704304128 4879706850936 4926562746624 5140761126912 5311450461204 5405292342144 5542383089952 5595602131968 5640305052672 5783356267776 6034806540288 6080953884912 6235180976196 6295052398464 6345343184256 6406272405504 6506275801248 6568750328832 6789157357824 7081933948272 7207056456192 7389844119936 7460802842624 7520406736896 7711141690368 7967175691806 8107938513216 8313574634928 8393403197952 8460457579008 8675034401664 8758333771776 8828303560704 9052209810432 9121430827368 9352771464294 9442578597696 9609408608256 9759413701872 9853125493248 10281522253824 10622900922408 10810584684288 11084766179904 11191204263936 11280610105344 11566712535552 11950763537709 12069613080576 12161907769824 12470361952392 12590104796928 12690686368512 13012551602496 13137500657664 13578314715648 14029157196441 14163867896544 14414112912384 14779688239872 15422283380736 15934351383612 16215877026432 16627149269856 16786806395904 16920915158016 17350068803328 18104419620864 18242861654736 18705542928588 18885157195392 19218817216512 19518827403744 19706250986496 21245801844816 21621169368576 22169532359808 22382408527872 22561220210688 23133425071104 23901527075418 24323815539648 24940723904784 25180209593856 25381372737024 26025103204992 26275001315328 27156629431296 28058314392882 28327735793088 28828225824768 29559376479744 30844566761472 31868702767224 32431754052864 33254298539712 33573612791808 33841830316032 34700137606656 35852290613127 36208839241728 36485723309472 37411085857176 37770314390784 39037654807488 39412501972992 42491603689632 43242338737152 44339064719616 46266850142208 47803054150836 48647631079296 49881447809568 50360419187712 50762745474048 52050206409984 54313258862592 56116628785764 56655471586176 57656451649536 59118752959488 63737405534448 64863508105728 66508597079424 67147225583616 67683660632064 69400275213312 71704581226254 72971446618944 74822171714352 75540628781568 78075309614976 78825003945984 84983207379264 86484677474304 88678129439232 92533700284416 95606108301672 97295262158592 99762895619136 100720838375424 101525490948096 104100412819968 107556871839381 108626517725184 112233257571528 113310943172352 118237505918976 127474811068896 129727016211456 133017194158848 138800550426624 143409162452508 145942893237888 149644343428704 151081257563136 156150619229952 169966414758528 172969354948608 177356258878464 191212216603344 194590524317184 199525791238272 201441676750848 203050981896192 208200825639936 215113743678762 224466515143056 226621886344704 236475011837952 254949622137792 259454032422912 266034388317696 277601100853248 286818324905016 291885786475776 299288686857408 302162515126272 312301238459904 322670615518143 339932829517056 354712517756928 382424433206688 389181048634368 399051582476544 416401651279872 430227487357524 448933030286112 453243772689408 509899244275584 518908064845824 532068776635392 573636649810032 583771572951552 598577373714816 604325030252544 624602476919808 645341231036286 679865659034112 709425035513856 764848866413376 778362097268736 798103164953088 832803302559744 860454974715048 897866060572224 906487545378816 1019798488551168 1064137553270784 1147273299620064 1167543145903104 1197154747429632 1249204953839616 1290682462072572 1359731318068224 1529697732826752 1556724194537472 1596206329906176 1720909949430096 1795732121144448 1812975090757632 2039596977102336 2128275106541568 2294546599240128 2335086291806208 2394309494859264 2498409907679232 2581364924145144 2719462636136448 3059395465653504 3192412659812352 3441819898860192 3591464242288896 4079193954204672 4589093198480256 4670172583612416 4788618989718528 5162729848290288 5438925272272896 6118790931307008 6384825319624704 6883639797720384 7182928484577792 8158387908409344 9178186396960512 9577237979437056 10325459696580576 12237581862614016 13767279595440768 14365856969155584 16316775816818688 18356372793921024 19154475958874112 20650919393161152 24475163725228032 27534559190881536 28731713938311168 36712745587842048 41301838786322304 48950327450456064 55069118381763072 57463427876622336 73425491175684096 82603677572644608 110138236763526144 146850982351368192 165207355145289216 220276473527052288 330414710290578432 440552947054104576 660829420581156864 1321658841162313728
- Sum of all divisors σ(n): 4159334439733374720
- Sum of proper divisors (its aliquot sum) s(n): 2837675598571060992
- 1321658841162313728 is an abundant number, because the sum of its proper divisors (2837675598571060992) is greater than itself. Its abundance is 1516016757408747264
Bases of 1321658841162313728
- Binary: 10010010101110111100110110110101011011011101111110000000000002
- Hexadecimal: 0x125779B6ADBBF000
- Base-36: A1HKYHO00000
Squares and roots of 1321658841162313728
- 1321658841162313728 squared (13216588411623137282) is 1746782092422510028280084242297257984
- 1321658841162313728 cubed (13216588411623137283) is 2308649996034216199712271516864483066132759771560804352
-
The
square root of 1321658841162313728 is 1149634220.5946697235 -
The
cube root of 1321658841162313728 is 1097420.6344366443
Scales and comparisons
How big is 1321658841162313728?- 1,321,658,841,162,313,728 seconds is equal to 42,024,662,989 years, 38 weeks, 5 days, 12 hours, 28 minutes, 48 seconds.
-
To count from 1 to 1,321,658,841,162,313,728 would take you about one hundred forty-seven billion, eighty-six million, three hundred twenty thousand, four hundred sixty-four 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 1321658841162313728 cubic inches would be around 91451.7 feet tall.
Recreational maths with 1321658841162313728
- 1321658841162313728 backwards is 8273132611488561231
- 1321658841162313728 is a
Harshad number . - The number of decimal digits it has is: 19
- The sum of 1321658841162313728's digits is 72
- 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 1321658841162313728 - Facts about the integer". Numbermatics.com. 2024. Web. 9 June 2024.
APA style:
Numbermatics. (2024). Number 1321658841162313728 - Facts about the integer. Retrieved 9 June 2024, from https://numbermatics.com/n/1321658841162313728/
Chicago style:
Numbermatics. 2024. "Number 1321658841162313728 - Facts about the integer". https://numbermatics.com/n/1321658841162313728/
The information we have on file for 1321658841162313728 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 1321658841162313728, math, Factors of 1321658841162313728, curriculum, school, college, exams, university, Prime factorization of 1321658841162313728, STEM, science, technology, engineering, physics, economics, calculator, one quintillion, three hundred twenty-one quadrillion, six hundred fifty-eight trillion, eight hundred forty-one billion, one hundred sixty-two million, three hundred thirteen thousand, seven hundred twenty-eight.