71545420779840
71,545,420,779,840 is an even composite number composed of seven prime numbers multiplied together.
What does the number 71545420779840 look like?
This visualization shows the relationship between its 7 prime factors (large circles) and 2268 divisors.
71545420779840 is an even composite number. It is composed of seven distinct prime numbers multiplied together. It has a total of two thousand, two hundred sixty-eight divisors.
Prime factorization of 71545420779840:
26 × 32 × 5 × 72 × 17 × 432 × 1272
(2 × 2 × 2 × 2 × 2 × 2 × 3 × 3 × 5 × 7 × 7 × 17 × 43 × 43 × 127 × 127)See below for interesting mathematical facts about the number 71545420779840 from the Numbermatics database.
Names of 71545420779840
- Cardinal: 71545420779840 can be written as Seventy-one trillion, five hundred forty-five billion, four hundred twenty million, seven hundred seventy-nine thousand, eight hundred forty.
Scientific notation
- Scientific notation: 7.154542077984 × 1013
Factors of 71545420779840
Divisors of 71545420779840
- Number of divisors d(n): 2268
-
Complete list of divisors:
1 2 3 4 5 6 7 8 9 10 12 14 15 16 17 18 20 21 24 28 30 32 34 35 36 40 42 43 45 48 49 51 56 60 63 64 68 70 72 80 84 85 86 90 96 98 102 105 112 119 120 126 127 129 136 140 144 147 153 160 168 170 172 180 192 196 204 210 215 224 238 240 245 252 254 255 258 272 280 288 294 301 306 315 320 336 340 344 357 360 381 387 392 408 420 430 441 448 476 480 490 504 508 510 516 544 560 576 588 595 602 612 630 635 645 672 680 688 714 720 731 735 762 765 774 784 816 833 840 860 882 889 903 952 960 980 1008 1016 1020 1032 1071 1088 1120 1143 1176 1190 1204 1224 1260 1270 1290 1344 1360 1376 1428 1440 1462 1470 1505 1524 1530 1548 1568 1632 1666 1680 1720 1764 1778 1785 1806 1849 1904 1905 1935 1960 2016 2032 2040 2064 2107 2142 2159 2193 2205 2240 2286 2352 2380 2408 2448 2499 2520 2540 2580 2667 2709 2720 2752 2856 2880 2924 2940 3010 3048 3060 3096 3136 3264 3332 3360 3440 3528 3556 3570 3612 3655 3698 3808 3810 3870 3920 4032 4064 4080 4128 4165 4214 4284 4318 4386 4410 4445 4515 4572 4704 4760 4816 4896 4998 5040 5080 5117 5160 5334 5355 5418 5440 5461 5547 5712 5715 5848 5880 6020 6096 6120 6192 6223 6321 6477 6579 6664 6720 6880 7056 7112 7140 7224 7310 7396 7497 7616 7620 7740 7840 8001 8128 8160 8256 8330 8428 8568 8636 8772 8820 8890 9030 9144 9245 9408 9520 9632 9792 9996 10080 10160 10234 10320 10535 10668 10710 10795 10836 10922 10965 11094 11424 11430 11696 11760 12040 12192 12240 12384 12446 12495 12642 12943 12954 13158 13328 13335 13545 13760 14112 14224 14280 14448 14620 14792 14994 15113 15240 15351 15480 15680 16002 16129 16320 16383 16641 16660 16856 17136 17272 17544 17640 17780 18060 18288 18490 18669 18963 19040 19264 19431 19992 20160 20320 20468 20640 21070 21336 21420 21590 21672 21844 21930 22188 22848 22860 23392 23520 24080 24384 24480 24768 24892 24990 25284 25585 25886 25908 26316 26656 26670 27090 27305 27735 28224 28448 28560 28896 29240 29584 29988 30226 30480 30702 30960 31115 31433 31605 32004 32258 32385 32766 32895 33282 33320 33712 34272 34544 35088 35280 35560 35819 36120 36576 36980 37338 37485 37926 38080 38227 38829 38862 39984 40005 40640 40936 41280 42140 42672 42840 43180 43344 43688 43860 44376 45339 45720 46053 46784 47040 48160 48387 48960 49149 49784 49980 50568 51170 51772 51816 52632 53312 53340 54180 54610 55470 56007 56896 57120 57792 58480 59168 59976 60452 60960 61404 61920 62230 62866 63210 64008 64516 64715 64770 65532 65790 66564 66640 67424 68544 69088 70176 70560 71120 71638 72240 73152 73960 74676 74970 75565 75852 76454 76755 77658 77724 79968 80010 80645 81872 81915 83205 84280 85344 85680 86360 86688 87376 87720 88752 90601 90678 91440 92106 92837 93345 94299 94815 96320 96774 97155 98298 99568 99960 101136 102340 103544 103632 105264 105791 106680 107457 108360 109220 110940 112014 112903 114240 114681 116487 116960 118336 119952 120904 121920 122808 123840 124460 125732 126420 128016 129032 129430 129540 131064 131580 133128 133280 134848 136017 138176 140352 141120 142240 143276 144480 145161 147920 149352 149940 151130 151704 152908 153510 155316 155448 157165 159936 160020 161290 163744 163830 166410 168560 170688 171360 172720 173376 174752 175440 177504 179095 181202 181356 182880 184212 185674 186690 188598 189630 191135 193548 194145 194310 196596 199136 199920 202272 204680 207088 207264 210528 211582 213360 214914 216720 218440 220031 221880 224028 225806 226695 229362 230265 232974 233920 234823 239904 241808 241935 245616 245745 248920 251464 252840 256032 258064 258860 259080 262128 263160 266256 266560 267589 271803 272034 274193 278511 280035 282897 284480 286552 288960 290322 295840 298704 299880 302260 303408 305816 307020 310632 310896 314330 317373 320040 322371 322580 327488 327660 332820 337120 338709 342720 344043 345440 349504 350880 355008 358190 362404 362712 365760 368424 371348 373380 377196 379260 382270 387096 388290 388620 393192 398272 399840 404544 409360 414176 414528 421056 423164 426720 429828 433440 436880 440062 443760 448056 451612 453005 453390 458724 460530 464185 465948 469646 471495 479808 483616 483870 491232 491490 497840 502928 505680 512064 516128 517720 518160 524256 526320 528955 532512 535178 537285 543606 544068 548386 557022 560070 564515 565794 573104 573405 580644 582435 591680 597408 599760 604520 606816 611632 614040 621264 621792 628660 634746 640080 644742 645160 649859 655320 660093 665640 674240 677418 680085 688086 690880 693547 701760 704469 716380 724808 725424 725805 736848 742696 746760 754392 758520 764540 774192 776580 777240 786384 790321 799680 802767 815409 818720 822579 828352 835533 846328 853440 859656 866880 873760 880124 887520 896112 903224 906010 906780 917448 921060 928370 931896 939292 942990 952119 967232 967740 982464 982980 995680 1005856 1011360 1016127 1032256 1035440 1036320 1048512 1052640 1057910 1065024 1070356 1074570 1087212 1088136 1096772 1100155 1114044 1120140 1129030 1131588 1146208 1146810 1161288 1164870 1174115 1194816 1199520 1209040 1213632 1223264 1228080 1242528 1243584 1257320 1269492 1280160 1289484 1290320 1299718 1310640 1320186 1331280 1337945 1354836 1359015 1360170 1370965 1376172 1387094 1392555 1408938 1414485 1432760 1449616 1450848 1451610 1473696 1485392 1493520 1508784 1517040 1529080 1540217 1548384 1553160 1554480 1572768 1580642 1586865 1605534 1611855 1630818 1637440 1643761 1645158 1671066 1692656 1693545 1719312 1720215 1747520 1760248 1775040 1792224 1806448 1812020 1813560 1834896 1842120 1856740 1863792 1878584 1885980 1904238 1919351 1935480 1949577 1965960 1980279 1991360 2011712 2022720 2032254 2070880 2072640 2080641 2105280 2113407 2115820 2140712 2149140 2174424 2176272 2193544 2200310 2228088 2240280 2258060 2263176 2292416 2293620 2322576 2329740 2348230 2370963 2399040 2408301 2418080 2446528 2456160 2467737 2485056 2514640 2538984 2560320 2578968 2580640 2599436 2621280 2640372 2662560 2675890 2709672 2718030 2720340 2741930 2752344 2774188 2785110 2817876 2828970 2865520 2899232 2901696 2903220 2947392 2970784 2987040 3017568 3034080 3058160 3080434 3096768 3106320 3108960 3145536 3161284 3173730 3211068 3223710 3249295 3261636 3287522 3290316 3300465 3342132 3385312 3387090 3438624 3440430 3467735 3520496 3522345 3584448 3612896 3624040 3627120 3669792 3684240 3713480 3727584 3757168 3771960 3808476 3838702 3870960 3899154 3931920 3951605 3960558 3991991 4013835 4064508 4077045 4112895 4141760 4161282 4177665 4226814 4231640 4281424 4298280 4348848 4352544 4387088 4400620 4456176 4480560 4516120 4526352 4549013 4587240 4620651 4645152 4659480 4696460 4741926 4760595 4816602 4836160 4854829 4912320 4931283 4935474 5029280 5077968 5080635 5157936 5161280 5198872 5242560 5280744 5325120 5351780 5419344 5436060 5440680 5483860 5504688 5548376 5570220 5635752 5657940 5731040 5758053 5798464 5806440 5848731 5941568 5974080 6035136 6068160 6116320 6160868 6212640 6217920 6241923 6322568 6347460 6422136 6447420 6498590 6523272 6575044 6580632 6600930 6684264 6770624 6774180 6877248 6880860 6935470 7040992 7044690 7112889 7225792 7248080 7254240 7339584 7368480 7426960 7455168 7514336 7543920 7616952 7677404 7701085 7741920 7798308 7863840 7903210 7921116 7983982 8027670 8129016 8154090 8218805 8225790 8322564 8355330 8453628 8463280 8562848 8596560 8697696 8705088 8774176 8801240 8912352 8961120 9032240 9052704 9098026 9174480 9241302 9290304 9318960 9392920 9483852 9521190 9596755 9633204 9709658 9747885 9862566 9870948 9901395 10058560 10155936 10161270 10315872 10397744 10403205 10561488 10567035 10703560 10838688 10872120 10881360 10967720 11009376 11096752 11140440 11271504 11315880 11462080 11506327 11516106 11612880 11697462 11790299 11854815 11975973 12041505 12232640 12321736 12338685 12425280 12483846 12645136 12694920 12844272 12894840 12997180 13046544 13150088 13161264 13201860 13368528 13435457 13548360 13647039 13761720 13861953 13870940 14081984 14089380 14225778 14496160 14508480 14564487 14736960 14793849 14853920 15028672 15087840 15233904 15354808 15402170 15483840 15596616 15727680 15806420 15842232 15967964 16055340 16258032 16308180 16437610 16451580 16645128 16710660 16907256 16926560 17125696 17193120 17274159 17395392 17548352 17602480 17824704 17922240 18064480 18105408 18196052 18348960 18482604 18637920 18785840 18967704 19042380 19193510 19266408 19419316 19495770 19725132 19741896 19802790 19959955 20311872 20322540 20631744 20795488 20806410 21122976 21134070 21407120 21677376 21744240 21762720 21935440 22018752 22193504 22280880 22543008 22631760 22745065 23012654 23032212 23103255 23225760 23394924 23580598 23709630 23951946 24083010 24274145 24643472 24656415 24677370 24967692 25290272 25389840 25688544 25789680 25994360 26093088 26300176 26322528 26403720 26737056 26870914 27096720 27294078 27523440 27723906 27741880 27943937 28178760 28451556 28790265 28992320 29128974 29243655 29587698 29707840 29822521 30175680 30467808 30709616 30804340 31193232 31209615 31612840 31684464 31935928 32110680 32516064 32616360 32875220 32903160 33290256 33421320 33814512 33853120 33983803 34386240 34518981 34548318 35204960 35370897 35564445 35927919 36128960 36392104 36697920 36965208 37275840 37571680 37935408 38084760 38387020 38532816 38838632 38991540 39450264 39483792 39605580 39919910 40306371 40645080 40941117 41590976 41612820 42245952 42268140 42814240 43488480 43525440 43693461 43870880 44387008 44561760 45086016 45263520 45490130 46025308 46064424 46206510 46451520 46789848 47161196 47419260 47903892 48166020 48548290 49286944 49312830 49354740 49935384 50580544 50779680 51377088 51579360 51988720 52186176 52600352 52645056 52807440 53474112 53741828 54193440 54588156 55046880 55447812 55483760 55887874 56357520 56903112 57531635 57580530 58257948 58487310 58951495 59175396 59645042 59879865 60935616 61419232 61608680 62386464 62419230 63225680 63368928 63871856 64221360 65032128 65232720 65750440 65806320 66580512 66842640 67177285 67629024 67967606 68235195 69037962 69096636 69309765 70409920 70741794 71128890 71855838 72784208 72822435 73930416 73969245 75143360 75870816 76169520 76774040 77065632 77677264 77983080 78900528 78967584 79211160 79839820 80612742 81290160 81882234 82532093 83225640 83831811 84536280 85628480 86370795 86976960 87386922 87741760 89123520 89467563 90527040 90980260 92050616 92128848 92413020 93579696 94322392 94838520 95807784 96332040 97096580 98573888 98625660 98709480 99870768 101559360 101951409 103158720 103556943 103977440 105200704 105614880 106112691 107483656 108386880 109176312 110093760 110895624 110967520 111775748 112715040 113806224 115063270 115161060 116515896 116974620 117902990 118350792 119290084 119759730 120919113 122838464 123217360 124772928 124838460 126451360 126737856 127743712 128442720 130465440 131500880 131612640 133161024 133685280 134354570 135258048 135935212 136470390 138075924 138193272 138619530 139719685 141483588 142257780 143711676 145568416 145644870 147860832 147938490 149112605 151741632 152339040 153548080 154131264 155354528 155966160 157801056 157935168 158422320 159679640 161225484 162580320 163764468 165064186 166451280 167663622 169072560 169919015 172594905 172741590 174773844 176854485 178935126 179639595 181960520 184101232 184257696 184826040 187159392 188644784 189677040 191615568 192664080 194193160 195607559 197251320 197418960 199741536 201531855 203902818 204705585 207113886 207954880 208757647 211229760 212225382 214967312 218352624 218467305 221791248 221935040 223551496 225430080 227612448 230126540 230322120 233031792 233949240 235805980 236701584 238580168 239519460 241838226 246434720 247596279 249676920 251495433 252902720 255487424 256885440 260930880 263001760 263225280 267370560 268402689 268709140 271870424 272940780 276151848 276386544 277239060 279439370 282967176 284515560 287423352 291136832 291289740 295721664 295876980 298225210 304678080 305854227 307096160 310709056 311932320 315602112 316844640 319359280 322450968 325160640 327528936 330128372 332902560 335327244 338145120 339838030 345189810 345483180 349547688 353708970 357870252 359279190 363921040 368202464 368515392 369652080 374318784 377289568 379354080 383231136 385328160 388386320 391215118 394502640 394837920 399483072 403063710 407805636 409411170 412660465 414227772 417515294 419159055 424450764 429934624 436705248 436934610 443582496 447102992 447337815 455224896 460253080 460644240 466063584 467898480 471611960 473403168 477160336 479038920 483676452 492869440 495192558 499353840 502990866 506982857 509757045 517784715 526003520 530563455 536805378 537418280 543740848 545881560 552303696 552773088 554478120 558878740 565934352 569031120 574846704 577724651 582579480 586822677 591753960 596450420 604595565 611708454 614192320 623864640 626272941 633689280 638718560 644901936 655057872 660256744 665805120 670654488 676290240 679676060 690379620 690966360 699095376 707417940 715740504 718558380 727842080 736404928 739304160 742788837 754579136 758708160 766462272 770656320 776772640 782430236 789005280 789675840 806127420 815611272 818822340 825320930 828455544 835030588 838318110 848901528 859869248 873410496 873869220 887164992 894205984 894675630 920506160 921288480 932127168 935796960 943223920 946806336 954320672 958077840 967352904 978037795 990385116 998707680 1005981732 1013965714 1019514090 1035569430 1043788235 1061126910 1073610756 1074836560 1087481696 1091763120 1104607392 1105546176 1108956240 1117757480 1131868704 1138062240 1149693408 1155449302 1165158960 1173645354 1183507920 1192900840 1209191130 1223416908 1237981395 1252545882 1257477165 1277437120 1289803872 1310115744 1320513488 1341308976 1342013445 1359352120 1380759240 1381932720 1398190752 1414835880 1431481008 1437116760 1455684160 1461303529 1478608320 1485577674 1520948571 1529271135 1553545280 1564860472 1578010560 1612254840 1631222544 1637644680 1650641860 1656911088 1670061176 1676636220 1697803056 1733173953 1747738440 1760468031 1788411968 1789351260 1841012320 1842576960 1871593920 1878818823 1886447840 1908641344 1916155680 1934705808 1956075590 1980770232 1997415360 2011963464 2027931428 2039028180 2071138860 2087576470 2122253820 2147221512 2149673120 2174963392 2183526240 2209214784 2217912480 2235514960 2263737408 2276124480 2299386816 2310898604 2330317920 2347290708 2367015840 2385801680 2418382260 2446833816 2475962790 2505091764 2514954330 2534914285 2579607744 2620231488 2641026976 2682617952 2684026890 2718704240 2761518480 2763865440 2796381504 2829671760 2862962016 2874233520 2888623255 2922607058 2934113385 2971155348 3041897142 3058542270 3129720944 3131364705 3224509680 3262445088 3275289360 3301283720 3313822176 3340122352 3353272440 3395606112 3466347906 3495476880 3520936062 3548879999 3578702520 3682024640 3713944185 3757637646 3772895680 3832311360 3869411616 3912151180 3961540464 4023926928 4055862856 4078056360 4142277720 4175152940 4244507640 4294443024 4299346240 4367052480 4383910587 4435824960 4471029920 4562845713 4621797208 4660635840 4694581416 4734031680 4771603360 4836764520 4893667632 4951925580 5010183528 5029908660 5069828570 5199521859 5282053952 5365235904 5368053780 5437408480 5523036960 5527730880 5659343520 5725924032 5748467040 5777246510 5845214116 5868226770 5942310696 6083794284 6117084540 6259441888 6262729410 6449019360 6524890176 6550578720 6602567440 6627644352 6680244704 6706544880 6791212224 6932695812 6990953760 7041872124 7097759998 7157405040 7306517645 7427888370 7515275292 7604742855 7738823232 7824302360 7923080928 8047853856 8111725712 8156112720 8284555440 8350305880 8489015280 8588886048 8665869765 8767821174 8802340155 8942059840 9125691426 9243594416 9389162832 9394094115 9543206720 9673529040 9787335264 9903851160 10020367056 10059817320 10139657140 10399043718 10646639997 10736107560 10874816960 11046073920 11318687040 11496934080 11554493020 11690428232 11736453540 11884621392 12167588568 12234169080 12518883776 12525458820 12898038720 13101157440 13151731761 13205134880 13360489408 13413089760 13865391624 13981907520 14083744248 14195519996 14314810080 14613035290 14855776740 15030550584 15209485710 15648604720 15846161856 16095707712 16223451424 16312225440 16569110880 16700611760 16978030560 17177772096 17331739530 17535642348 17604680310 17744399995 18251382852 18487188832 18778325664 18788188230 19347058080 19574670528 19807702320 20040734112 20119634640 20279314280 20798087436 21293279994 21472215120 21919552935 22814228565 23108986040 23380856464 23472907080 23769242784 24335177136 24468338160 24842159993 25050917640 25997609295 26303463522 26410269760 26826179520 27730783248 28167488496 28391039992 28629620160 29226070580 29711553480 30061101168 30418971420 31297209440 31939919991 32446902848 32624450880 33138221760 33401223520 33956061120 34663479060 35071284696 35209360620 35488799990 36502765704 36974377664 37556651328 37576376460 38694116160 39615404640 40081468224 40239269280 40558628560 41596174872 42586559988 42944430240 43839105870 45628457130 46217972080 46761712928 46945814160 47538485568 48670354272 48936676320 49684319986 50101835280 51995218590 52606927044 53233199985 55461566496 56334976992 56782079984 58452141160 59423106960 60122202336 60837942840 62594418880 63879839982 65758658805 66802447040 69326958120 70142569392 70418721240 70977599980 73005531408 74526479979 75152752920 79230809280 80478538560 81117257120 83192349744 85173119976 85888860480 87678211740 91256914260 92435944160 93523425856 93891628320 97340708544 97873352640 99368639972 100203670560 103990437180 105213854088 106466399970 110923132992 112669953984 113564159968 116904282320 118846213920 120244404672 121675885680 124210799965 127759679964 131517317610 138653916240 140285138784 140837442480 141955199960 146011062816 149052959958 150305505840 159699599955 162234514240 166384699488 170346239952 175356423480 182513828520 184871888320 187783256640 198737279944 200407341120 207980874360 210427708176 212932799940 223579439937 227128319936 233808564640 237692427840 243351771360 248421599930 255519359928 263034635220 277307832480 280570277568 281674884960 283910399920 292022125632 298105919916 300611011680 319399199910 332769398976 340692479904 350712846960 365027657040 372632399895 397474559888 415961748720 420855416352 425865599880 447158879874 467617129280 486703542720 496843199860 511038719856 526069270440 554615664960 563349769920 567820799840 596211839832 601222023360 638798399820 681384959808 701425693920 730055314080 745264799790 794949119776 831923497440 841710832704 851731199760 894317759748 993686399720 1022077439712 1052138540880 1117897199685 1135641599680 1192423679664 1277596799640 1402851387840 1460110628160 1490529599580 1589898239552 1663846994880 1703462399520 1788635519496 1987372799440 2044154879424 2104277081760 2235794399370 2384847359328 2555193599280 2981059199160 3406924799040 3577271038992 3974745598880 4208554163520 4471588798740 4769694718656 5110387198560 5962118398320 7154542077984 7949491197760 8943177597480 10220774397120 11924236796640 14309084155968 17886355194960 23848473593280 35772710389920 71545420779840
- Sum of all divisors σ(n): 312778364285556
- Sum of proper divisors (its aliquot sum) s(n): 241232943505716
- 71545420779840 is an abundant number, because the sum of its proper divisors (241232943505716) is greater than itself. Its abundance is 169687522725876
Bases of 71545420779840
- Binary: 100000100010001111101110110010000010001010000002
- Hexadecimal: 0x4111F7641140
- Base-36: PCZIGA8G0
Squares and roots of 71545420779840
- 71545420779840 squared (715454207798402) is 5118747234564361273750425600
- 71545420779840 cubed (715454207798403) is 366222924762549587764880670452283899904000
-
The
square root of 71545420779840 is 8458452.6232544449 -
The
cube root of 71545420779840 is 41513.9394369377
Scales and comparisons
How big is 71545420779840?- 71,545,420,779,840 seconds is equal to 2,274,923 years, 3 weeks, 6 days, 18 hours, 24 minutes.
-
To count from 1 to 71,545,420,779,840 would take you about five million, six hundred eighty-seven thousand, three hundred seven 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 71545420779840 cubic inches would be around 3459.5 feet tall.
Recreational maths with 71545420779840
- 71545420779840 backwards is 04897702454517
- 71545420779840 is a
Harshad number . - The number of decimal digits it has is: 14
- The sum of 71545420779840's digits is 63
- 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 71545420779840 - Facts about the integer". Numbermatics.com. 2024. Web. 21 June 2024.
APA style:
Numbermatics. (2024). Number 71545420779840 - Facts about the integer. Retrieved 21 June 2024, from https://numbermatics.com/n/71545420779840/
Chicago style:
Numbermatics. 2024. "Number 71545420779840 - Facts about the integer". https://numbermatics.com/n/71545420779840/
The information we have on file for 71545420779840 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 71545420779840, math, Factors of 71545420779840, curriculum, school, college, exams, university, Prime factorization of 71545420779840, STEM, science, technology, engineering, physics, economics, calculator, seventy-one trillion, five hundred forty-five billion, four hundred twenty million, seven hundred seventy-nine thousand, eight hundred forty.