81687998720

Names of 81687998720

• Cardinal: 81687998720 can be written as Eighty-one billion, six hundred eighty-seven million, nine hundred ninety-eight thousand, seven hundred twenty.

Scientific notation

• Scientific notation: 8.168799872 × 10¹⁰

Factors of 81687998720

• Number of distinct prime factors ω(n): 5
• Total number of prime factors Ω(n): 12
• Sum of prime factors: 3078

Divisors of 81687998720

• Number of divisors d(n): 144
• Complete list of divisors:
  1 2 4 5 8 10 16 20 32 40 61 64 80 122 128 160 244 256 305 320 401 488 610 640 802 976 1220 1280 1604 1952 2005 2440 2609 3208 3904 4010 4880 5218 6416 7808 8020 9760 10436 12832 13045 15616 16040 19520 20872 24461 25664 26090 32080 39040 41744 48922 51328 52180 64160 78080 83488 97844 102656 104360 122305 128320 159149 166976 195688 208720 244610 256640 318298 333952 391376 417440 489220 513280 636596 667904 782752 795745 834880 978440 1046209 1273192 1565504 1591490 1669760 1956880 2092418 2546384 3131008 3182980 3339520 3913760 4184836 5092768 5231045 6262016 6365960 7827520 8369672 10185536 10462090 12731920 15655040 16739344 20371072 20924180 25463840 31310080 33478688 40742144 41848360 50927680 63818749 66957376 83696720 101855360 127637498 133914752 167393440 203710720 255274996 267829504 319093745 334786880 510549992 638187490 669573760 1021099984 1276374980 1339147520 2042199968 2552749960 4084399936 5105499920 8168799872 10210999840 16337599744 20421999680 40843999360 81687998720
• Sum of all divisors σ(n): 199448328240
• Sum of proper divisors (its aliquot sum) s(n): 117760329520
• 81687998720 is an abundant number, because the sum of its proper divisors (117760329520) is greater than itself. Its abundance is 36072330800

Bases of 81687998720

• Binary: 1001100000100111110111111000100000000₂
• Hexadecimal: 0x1304FBF100
• Base-36: 11IYXB7K

Squares and roots of 81687998720

• 81687998720 squared (81687998720²) is 6672929134878721638400
• 81687998720 cubed (81687998720³) is 545098226628623720552855502848000
• The square root of 81687998720 is 285811.1242061791
• The cube root of 81687998720 is 4338.9643858299

Scales and comparisons

• 81,687,998,720 seconds is equal to 2,597 years, 22 weeks, 22 hours, 45 minutes, 20 seconds.
• To count from 1 to 81,687,998,720 would take you about five thousand, one hundred ninety-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 81687998720 cubic inches would be around 361.6 feet tall.

Recreational maths with 81687998720

• 81687998720 backwards is 02789978618
• The number of decimal digits it has is: 11
• The sum of 81687998720's digits is 65
• More coming soon!