9009928376281800
9,009,928,376,281,800 is an even composite number composed of five prime numbers multiplied together.
What does the number 9009928376281800 look like?
This visualization shows the relationship between its 5 prime factors (large circles) and 2052 divisors.
9009928376281800 is an even composite number. It is composed of five distinct prime numbers multiplied together. It has a total of two thousand and fifty-two divisors.
Prime factorization of 9009928376281800:
23 × 318 × 52 × 112 × 312
(2 × 2 × 2 × 3 × 3 × 3 × 3 × 3 × 3 × 3 × 3 × 3 × 3 × 3 × 3 × 3 × 3 × 3 × 3 × 3 × 3 × 5 × 5 × 11 × 11 × 31 × 31)See below for interesting mathematical facts about the number 9009928376281800 from the Numbermatics database.
Names of 9009928376281800
- Cardinal: 9009928376281800 can be written as Nine quadrillion, nine trillion, nine hundred twenty-eight billion, three hundred seventy-six million, two hundred eighty-one thousand, eight hundred.
Scientific notation
- Scientific notation: 9.0099283762818 × 1015
Factors of 9009928376281800
Divisors of 9009928376281800
- Number of divisors d(n): 2052
-
Complete list of divisors:
1 2 3 4 5 6 8 9 10 11 12 15 18 20 22 24 25 27 30 31 33 36 40 44 45 50 54 55 60 62 66 72 75 81 88 90 93 99 100 108 110 120 121 124 132 135 150 155 162 165 180 186 198 200 216 220 225 242 243 248 264 270 275 279 297 300 310 324 330 341 360 363 372 396 405 440 450 465 484 486 495 540 550 558 594 600 605 620 648 660 675 682 726 729 744 775 792 810 825 837 891 900 930 961 968 972 990 1023 1080 1089 1100 1116 1188 1210 1215 1240 1320 1350 1364 1395 1452 1458 1485 1550 1620 1650 1674 1705 1782 1800 1815 1860 1922 1944 1980 2025 2046 2178 2187 2200 2232 2325 2376 2420 2430 2475 2511 2673 2700 2728 2790 2883 2904 2916 2970 3025 3069 3100 3240 3267 3300 3348 3410 3564 3630 3645 3720 3751 3844 3960 4050 4092 4185 4356 4374 4455 4650 4805 4840 4860 4950 5022 5115 5346 5400 5445 5580 5766 5832 5940 6050 6075 6138 6200 6534 6561 6600 6696 6820 6975 7128 7260 7290 7425 7502 7533 7688 8019 8100 8184 8370 8525 8649 8712 8748 8910 9075 9207 9300 9610 9720 9801 9900 10044 10230 10571 10692 10890 10935 11160 11253 11532 11880 12100 12150 12276 12555 13068 13122 13365 13640 13950 14415 14520 14580 14850 15004 15066 15345 16038 16200 16335 16740 17050 17298 17496 17820 18150 18225 18414 18600 18755 19220 19602 19683 19800 20088 20460 20925 21142 21384 21780 21870 22275 22506 22599 23064 24025 24057 24200 24300 24552 25110 25575 25947 26136 26244 26730 27225 27621 27900 28830 29160 29403 29700 30008 30132 30690 31713 32076 32670 32805 33480 33759 34100 34596 35640 36300 36450 36828 37510 37665 38440 39204 39366 40095 40920 41850 42284 43245 43560 43740 44550 45012 45198 46035 48050 48114 48600 49005 50220 51150 51894 52488 52855 53460 54450 54675 55242 55800 56265 57660 58806 59049 59400 60264 61380 62775 63426 64152 65340 65610 66825 67518 67797 68200 69192 72075 72171 72600 72900 73656 75020 75330 76725 77841 78408 78732 80190 81675 82863 83700 84568 86490 87480 88209 89100 90024 90396 92070 93775 95139 96100 96228 98010 98415 100440 101277 102300 103788 105710 106920 108900 109350 110484 112530 112995 115320 116281 117612 118098 120285 122760 125550 126852 129735 130680 131220 133650 135036 135594 138105 144150 144342 145800 147015 150040 150660 153450 155682 157464 158565 160380 163350 164025 165726 167400 168795 172980 176418 177147 178200 180792 184140 187550 188325 190278 192200 192456 196020 196830 200475 202554 203391 204600 207576 211420 216225 216513 217800 218700 220968 225060 225990 230175 232562 233523 235224 236196 240570 245025 248589 251100 253704 259470 262440 264275 264627 267300 270072 271188 276210 281325 285417 288300 288684 294030 295245 301320 303831 306900 311364 317130 320760 326700 328050 331452 337590 338985 345960 348843 352836 354294 360855 368280 375100 376650 380556 389205 392040 393660 400950 405108 406782 414315 422840 432450 433026 437400 441045 450120 451980 460350 465124 467046 472392 475695 481140 490050 492075 497178 502200 506385 518940 528550 529254 531441 534600 542376 552420 562650 564975 570834 576600 577368 581405 588060 590490 601425 607662 610173 613800 622728 634260 648675 649539 653400 656100 662904 675180 677970 690525 697686 700569 705672 708588 721710 735075 745767 750200 753300 761112 778410 787320 792825 793881 801900 810216 813564 828630 843975 856251 864900 866052 882090 885735 903960 911493 920700 930248 934092 951390 962280 980100 984150 994356 1012770 1016955 1037880 1046529 1057100 1058508 1062882 1082565 1104840 1125300 1129950 1141668 1162810 1167615 1176120 1180980 1202850 1215324 1220346 1242945 1268520 1297350 1299078 1312200 1323135 1350360 1355940 1381050 1395372 1401138 1417176 1427085 1443420 1470150 1476225 1491534 1506600 1519155 1556820 1585650 1587762 1594323 1603800 1627128 1657260 1687950 1694925 1712502 1729800 1732104 1744215 1764180 1771470 1804275 1822986 1830519 1841400 1868184 1902780 1946025 1948617 1960200 1968300 1988712 2025540 2033910 2071575 2093058 2101707 2114200 2117016 2125764 2165130 2205225 2237301 2250600 2259900 2283336 2325620 2335230 2361960 2378475 2381643 2405700 2430648 2440692 2485890 2531925 2568753 2594700 2598156 2646270 2657205 2711880 2734479 2762100 2790744 2802276 2854170 2886840 2907025 2940300 2952450 2983068 3038310 3050865 3113640 3139587 3171300 3175524 3188646 3247695 3314520 3375900 3389850 3425004 3488430 3502845 3528360 3542940 3608550 3645972 3661038 3728835 3805560 3892050 3897234 3936600 3969405 4051080 4067820 4143150 4186116 4203414 4251528 4281255 4330260 4410450 4428675 4474602 4519800 4557465 4651240 4670460 4756950 4763286 4782969 4811400 4881384 4971780 5063850 5084775 5137506 5189400 5196312 5232645 5292540 5314410 5412825 5468958 5491557 5524200 5604552 5708340 5814050 5838075 5845851 5880600 5904900 5966136 6076620 6101730 6214725 6279174 6305121 6342600 6351048 6377292 6495390 6615675 6711903 6751800 6779700 6850008 6976860 7005690 7085880 7135425 7144929 7217100 7291944 7322076 7457670 7595775 7706259 7784100 7794468 7938810 7971615 8135640 8203437 8286300 8372232 8406828 8562510 8660520 8721075 8820900 8857350 8949204 9114930 9152595 9340920 9418761 9513900 9526572 9565938 9743085 9943560 10127700 10169550 10275012 10465290 10508535 10585080 10628820 10825650 10937916 10983114 11186505 11416680 11628100 11676150 11691702 11809800 11908215 12153240 12203460 12429450 12558348 12610242 12754584 12843765 12990780 13231350 13286025 13423806 13559400 13672395 13953720 14011380 14270850 14289858 14348907 14434200 14644152 14915340 15191550 15254325 15412518 15568200 15588936 15697935 15877620 15943230 16238475 16406874 16474671 16572600 16813656 17125020 17442150 17514225 17537553 17641800 17714700 17898408 18229860 18305190 18644175 18837522 18915363 19027800 19053144 19131876 19486170 19847025 20135709 20255400 20339100 20550024 20930580 21017070 21257640 21406275 21434787 21651300 21875832 21966228 22373010 22787325 23118777 23256200 23352300 23383404 23816430 23914845 24406920 24610311 24858900 25116696 25220484 25687530 25981560 26163225 26462700 26572050 26847612 27344790 27457785 28022760 28256283 28541700 28579716 28697814 29229255 29830680 30383100 30508650 30825036 31395870 31525605 31755240 31886460 32476950 32813748 32949342 33559515 34250040 34884300 35028450 35075106 35429400 35724645 36459720 36610380 37288350 37675044 37830726 38263752 38531295 38972340 39694050 39858075 40271418 40678200 41017185 41861160 42034140 42812550 42869574 43046721 43302600 43932456 44746020 45574650 45762975 46237554 46704600 46766808 47093805 47632860 47829690 48715425 49220622 49424013 49717800 50440968 51375060 52326450 52542675 52612659 52925400 53144100 53695224 54689580 54915570 55932525 56512566 56746089 57083400 57159432 57395628 58458510 59541075 60407127 60766200 61017300 61650072 62791740 63051210 63772920 64218825 64304361 64953900 65627496 65898684 67119030 68361975 69356331 69768600 70056900 70150212 71449290 71744535 73220760 73830933 74576700 75350088 75661452 77062590 77944680 78489675 79388100 79716150 80542836 82034370 82373355 84068280 84768849 85625100 85739148 86093442 87687765 89492040 91149300 91525950 92475108 94187610 94576815 95265720 95659380 97430850 98441244 98848026 100678545 102750120 104652900 105085350 105225318 106288200 107173935 109379160 109831140 111865050 113025132 113492178 114791256 115593885 116917020 119082150 119574225 120814254 122034600 123051555 125583480 126102420 128437650 128608722 129140163 129907800 131797368 134238060 136723950 137288925 138712662 140113800 140300424 141281415 142898580 143489070 146146275 147661866 148272039 149153400 151322904 154125180 156979350 157628025 157837977 158776200 159432300 161085672 164068740 164746710 167797575 169537698 170238267 171250200 171478296 172186884 175375530 178623225 181221381 182298600 183051900 184950216 188375220 189153630 191318760 192656475 192913083 194861700 196882488 197696052 201357090 205085925 208068993 209305800 210170700 210450636 214347870 215233605 219662280 221492799 223730100 226050264 226984356 231187770 233834040 235469025 238164300 239148450 241628508 246103110 247120065 252204840 254306547 256875300 257217444 258280326 263063295 268476120 273447900 274577850 277425324 282562830 283730445 285797160 286978140 292292550 295323732 296544078 302035635 308250360 313958700 315256050 315675954 318864600 321521805 328137480 329493420 335595150 339075396 340476534 344373768 346781655 350751060 357246450 358722675 362442762 366103800 369154665 376750440 378307260 385312950 385826166 387420489 389723400 395392104 402714180 410171850 411866775 416137986 420341400 420901272 423844245 428695740 430467210 438438825 442985598 444816117 447460200 453968712 462375540 470938050 472884075 473513931 476328600 478296900 483257016 492206220 494240130 503392725 508613094 510714801 513750600 514434888 516560652 526126590 535869675 543664143 546895800 549155700 554850648 565125660 567460890 573956280 577969425 578739249 584585100 590647464 593088156 604071270 615257775 624206979 627917400 630512100 631351908 643043610 645700815 658986840 664478397 671190300 678150792 680953068 693563310 701502120 706407075 714492900 717445350 724885524 738309330 741360195 756614520 762919641 770625900 771652332 774840978 789189885 805428360 820343700 823733550 832275972 847688490 851191335 857391480 860934420 876877650 885971196 889632234 906106905 924751080 941876100 945768150 947027862 956593800 964565415 984412440 988480260 1006785450 1017226188 1021429602 1033121304 1040344965 1052253180 1071739350 1076168025 1087328286 1098311400 1107463995 1130251320 1134921780 1155938850 1157478498 1169170200 1186176312 1208142540 1230515550 1235600325 1248413958 1261024200 1262703816 1271532735 1286087220 1291401630 1315316475 1328956794 1334448351 1342380600 1361906136 1387126620 1412814150 1418652225 1420541793 1428985800 1434890700 1449771048 1476618660 1482720390 1510178175 1525839282 1532144403 1541251800 1543304664 1549681956 1578379770 1607609025 1630992429 1640687400 1647467100 1664551944 1695376980 1702382670 1721868840 1733908275 1736217747 1753755300 1771942392 1779264468 1812213810 1845773325 1872620937 1883752200 1891536300 1894055724 1929130830 1937102445 1976960520 1993435191 2013570900 2034452376 2042859204 2080689930 2104506360 2119221225 2143478700 2152336050 2174656572 2214927990 2224080585 2269843560 2288758923 2311877700 2314956996 2367569655 2416285080 2461031100 2471200650 2496827916 2543065470 2553574005 2572174440 2582803260 2630632950 2657913588 2668896702 2718320715 2774253240 2825628300 2837304450 2841083586 2869781400 2893696245 2953237320 2965440780 3020356350 3051678564 3064288806 3099363912 3121034895 3156759540 3215218050 3228504075 3261984858 3294934200 3322391985 3390753960 3404765340 3467816550 3472435494 3507510600 3558528936 3624427620 3691546650 3706800975 3745241874 3783072600 3788111448 3814598205 3858261660 3874204890 3945949425 3986870382 4003345053 4027141800 4085718408 4161379860 4238442450 4255956675 4261625379 4286957400 4304672100 4349313144 4429855980 4448161170 4530534525 4577517846 4596433209 4623755400 4629913992 4735139310 4822827075 4892977287 4922062200 4942401300 4993655832 5086130940 5107148010 5165606520 5201724825 5208653241 5261265900 5315827176 5337793404 5436641430 5537319975 5617862811 5651256600 5674608900 5682167172 5787392490 5930881560 5980305573 6040712700 6103357128 6128577612 6242069790 6313519080 6357663675 6430436100 6457008150 6523969716 6644783970 6672241755 6809530680 6866276769 6935633100 6944870988 7102708965 7248855240 7383093300 7413601950 7490483748 7629196410 7660722015 7716523320 7748409780 7891898850 7973740764 8006690106 8154962145 8322759720 8476884900 8511913350 8523250758 8609344200 8681088735 8859711960 8896322340 9061069050 9155035692 9192866418 9363104685 9470278620 9645654150 9685512225 9785954574 9884802600 9967175955 10172261880 10214296020 10403449650 10417306482 10522531800 10675586808 10873282860 11074639950 11120402925 11235725622 11349217800 11364334344 11443794615 11574784980 11837848275 11960611146 12010035159 12081425400 12257155224 12484139580 12715327350 12767870025 12860872200 12914016300 13047939432 13289567940 13344483510 13591603575 13732553538 13789299627 13871266200 13889741976 14205417930 14468481225 14678931861 14766186600 14827203900 14980967496 15258392820 15321444030 15496819560 15605174475 15625959723 15783797700 15947481528 16013380212 16309924290 16611959925 16853588433 16953769800 17023826700 17046501516 17362177470 17792644680 17940916719 18122138100 18310071384 18385732836 18726209370 18940557240 19072991025 19291308300 19371024450 19571909148 19934351910 20016725265 20428592040 20598830307 20806899300 20834612964 21308126895 21746565720 22149279900 22240805850 22471451244 22887589230 22982166045 23149569960 23675696550 23921222292 24020070318 24464886435 24968279160 25430654700 25535740050 25828032600 26043266205 26579135880 26688967020 27183207150 27465107076 27578599254 28089314055 28410835860 28936962450 29357863722 29654407800 29901527865 30516785640 30642888060 31210348950 31251919446 31567595400 32026760424 32619848580 33223919850 33361208775 33707176866 34047653400 34093003032 34331383845 34724354940 35513544825 35881833438 36244276200 36771465672 37452418740 38145982050 38303610075 38582616600 38742048900 39143818296 39868703820 40033450530 40774810725 41197660614 41367898881 41613798600 41669225928 42616253790 43405443675 44036795583 44298559800 44481611700 44942902488 45775178460 45964332090 46815523425 46877879169 47351393100 47842444584 48040140636 48929772870 49835879775 50560765299 50861309400 51071480100 52086532410 53377934040 53822750157 54366414300 54930214152 55157198508 56178628110 56821671720 57218973075 57873924900 58715727444 59803055730 60050175795 61285776120 61796490921 62420697900 62503838892 65239697160 66447839700 66722417550 67414353732 68662767690 68946498135 69448709880 71027089650 71763666876 73394659305 74904837480 76291964100 76607220150 77484097800 78129798615 79737407640 80066901060 81549621450 82395321228 82735797762 84267942165 85232507580 86810887350 88073591166 88963223400 89704583595 91550356920 91928664180 93631046850 93755758338 94702786200 96080281272 97859545740 99671759550 100083626325 101121530598 102142960200 102994151535 104173064820 106540634475 107645500314 108732828600 110314397016 112357256220 114437946150 114910830225 115747849800 117431454888 119606111460 120100351590 122324432175 123592981842 124103696643 124841395800 125007677784 130216331025 132110386749 132895679400 133444835100 134828707464 137325535380 137892996270 140446570275 142054179300 143527333752 146789318610 149507639325 151682295897 152583928200 153214440300 156259597230 160133802120 161468250471 163099242900 164790642456 165471595524 168535884330 170465015160 171656919225 173621774700 176147182332 179409167190 183857328360 185389472763 187262093700 187511516676 195719091480 199343519100 200167252650 202243061196 205988303070 206839494405 208346129640 213081268950 215291000628 220183977915 224714512440 228875892300 229821660450 234389395845 239212222920 240200703180 244648864350 247185963684 248207393286 252803826495 260432662050 264220773498 266889670200 269113750785 274651070760 275785992540 280893140550 284108358600 293578637220 299015278650 300250878975 303364591794 306428880600 308982454605 312519194460 322936500942 326198485800 330943191048 337071768660 343313838450 344732490675 347243549400 352294364664 358818334380 366973296525 370778945526 372311089929 374524187400 375023033352 390648993075 398687038200 400334505300 404486122392 411976606140 413678988810 421339710825 426162537900 430582001256 440367955830 448522917975 455046887691 457751784600 459643320900 468778791690 480401406360 484404751413 489297728700 494371927368 496414786572 505607652990 514970757675 520865324100 528441546996 538227501570 551571985080 556168418289 561786281100 587157274440 598030557300 600501757950 606729183588 617964909210 620518483215 625038388920 645873001884 660551933745 674143537320 686627676900 689464981350 717636668760 733946593050 741557891052 744622179858 758411479485 781297986150 800669010600 807341252355 823953212280 827357977620 842679421650 852325075800 880735911660 897045835950 910093775382 919286641800 926947363815 937557583380 968809502826 978595457400 992829573144 1011215305980 1029941515350 1034197472025 1041730648200 1056883093992 1076455003140 1100919889575 1112336836578 1123572562200 1171946979225 1196061114600 1201003515900 1213458367176 1235929818420 1241036966430 1264019132475 1291746003768 1321103867490 1345568753925 1365140663073 1373255353800 1378929962700 1453214254239 1467893186100 1483115782104 1489244359716 1516822958970 1544912273025 1562595972300 1614682504710 1654715955240 1668505254867 1685358843300 1761471823320 1794091671900 1820187550764 1853894727630 1861555449645 1875115166760 1937619005652 2022430611960 2059883030700 2068394944050 2152910006280 2201839779150 2224673673156 2275234438455 2343893958450 2402007031800 2422023757065 2471859636840 2482073932860 2528038264950 2642207734980 2691137507850 2730281326146 2757859925400 2780842091445 2906428508478 2935786372200 2978488719432 3033645917940 3089824546050 3102592416075 3125191944600 3229365009420 3302759668725 3337010509734 3370717686600 3588183343800 3640375101528 3707789455260 3723110899290 3792057397425 3875238011304 4036706261775 4095421989219 4119766061400 4136789888100 4403679558300 4449347346312 4550468876910 4634736819075 4687787916900 4844047514130 4964147865720 5005515764601 5056076529900 5284415469960 5382275015700 5460562652292 5561684182890 5812857016956 6067291835880 6179649092100 6205184832150 6458730018840 6605519337450 6674021019468 6825703315365 7266071271195 7415578910520 7446221798580 7584114794850 8073412523550 8190843978438 8273579776200 8342526274335 8807359116600 9100937753820 9269473638150 9307777248225 9375575833800 9688095028260 10011031529202 10112153059800 10764550031400 10921125304584 11123368365780 11376172192275 11625714033912 12110118785325 12359298184200 12410369664300 13211038674900 13348042038936 13651406630730 13904210457225 14532142542390 14892443597160 15016547293803 15168229589700 16146825047100 16381687956876 16685052548670 18201875507640 18538947276300 18615554496450 19376190056520 20022063058404 20477109946095 22246736731560 22752344384550 24220237570650 24820739328600 25027578823005 26422077349800 27302813261460 27808420914450 29064285084780 30033094587606 30336459179400 32293650094200 32763375913752 33370105097340 34128516576825 36330356355975 37077894552600 37231108992900 40044126116808 40954219892190 41712631371675 45049641881409 45504688769100 48440475141300 50055157646010 54605626522920 55616841828900 58128570169560 60066189175212 66740210194680 68257033153650 72660712711950 74462217985800 75082736469015 81908439784380 83425262743350 90099283762818 91009377538200 96880950282600 100110315292020 102385549730475 111233683657800 120132378350424 125137894115025 136514066307300 145321425423900 150165472938030 163816879568760 166850525486700 180198567525636 200220630584040 204771099460950 225248209407045 250275788230050 273028132614600 290642850847800 300330945876060 333701050973400 360397135051272 375413682345075 409542198921900 450496418814090 500551576460100 600661891752120 750827364690150 819084397843800 900992837628180 1001103152920200 1126241047035225 1501654729380300 1801985675256360 2252482094070450 3003309458760600 4504964188140900 9009928376281800
- Sum of all divisors σ(n): 35688449971108305
- Sum of proper divisors (its aliquot sum) s(n): 26678521594826505
- 9009928376281800 is an abundant number, because the sum of its proper divisors (26678521594826505) is greater than itself. Its abundance is 17668593218544705
Bases of 9009928376281800
- Binary: 1000000000001001111011011011000101000111101010110010002
- Hexadecimal: 0x20027B6C51EAC8
- Base-36: 2GPR3YDS4I0
Squares and roots of 9009928376281800
- 9009928376281800 squared (90099283762818002) is 81178809345727993008793011240000
- 9009928376281800 cubed (90099283762818003) is 731415257876844827061079917911640816807432000000
-
The
square root of 9009928376281800 is 94920642.5193266377 -
The
cube root of 9009928376281800 is 208084.8425477545
Scales and comparisons
How big is 9009928376281800?- 9,009,928,376,281,800 seconds is equal to 286,487,852 years, 43 weeks, 4 hours, 30 minutes.
-
To count from 1 to 9,009,928,376,281,800 would take you about eight hundred fifty-nine million, four hundred sixty-three thousand, five hundred fifty-eight 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 9009928376281800 cubic inches would be around 17340.4 feet tall.
Recreational maths with 9009928376281800
- 9009928376281800 backwards is 0081826738299009
- 9009928376281800 is a
Harshad number . - The number of decimal digits it has is: 16
- The sum of 9009928376281800'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 9009928376281800 - Facts about the integer". Numbermatics.com. 2024. Web. 2 May 2024.
APA style:
Numbermatics. (2024). Number 9009928376281800 - Facts about the integer. Retrieved 2 May 2024, from https://numbermatics.com/n/9009928376281800/
Chicago style:
Numbermatics. 2024. "Number 9009928376281800 - Facts about the integer". https://numbermatics.com/n/9009928376281800/
The information we have on file for 9009928376281800 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 9009928376281800, math, Factors of 9009928376281800, curriculum, school, college, exams, university, Prime factorization of 9009928376281800, STEM, science, technology, engineering, physics, economics, calculator, nine quadrillion, nine trillion, nine hundred twenty-eight billion, three hundred seventy-six million, two hundred eighty-one thousand, eight hundred.