81721218007

Names of 81721218007

• Cardinal: 81721218007 can be written as Eighty-one billion, seven hundred twenty-one million, two hundred eighteen thousand and seven.

Scientific notation

• Scientific notation: 8.1721218007 × 10¹⁰

Factors of 81721218007

• Number of distinct prime factors ω(n): 4
• Total number of prime factors Ω(n): 9
• Sum of prime factors: 148

Divisors of 81721218007

• Number of divisors d(n): 72
• Complete list of divisors:
  1 11 13 17 107 121 143 169 187 221 1177 1391 1573 1819 1859 2057 2197 2431 2873 12947 15301 18083 20009 20449 23647 24167 26741 28561 31603 37349 168311 198913 220099 235079 260117 265837 307411 314171 347633 371293 410839 485537 2188043 2585869 2861287 3056027 3381521 3455881 3996343 4084223 4519229 5340907 6311981 28444559 33616297 37196731 39728351 43959773 44926453 51952459 58749977 69431791 369779267 437011861 483557503 571477049 675381967 763749701 4807130471 6286247539 7429201637 81721218007
• Sum of all divisors σ(n): 103998405168
• Sum of proper divisors (its aliquot sum) s(n): 22277187161
• 81721218007 is a deficient number, because the sum of its proper divisors (22277187161) is less than itself. Its deficiency is 59444030846

Bases of 81721218007

• Binary: 1001100000110111101101101001111010111₂
• Hexadecimal: 0x1306F6D3D7
• Base-36: 11JIPBDJ

Squares and roots of 81721218007

• 81721218007 squared (81721218007²) is 6678357472547621052049
• 81721218007 cubed (81721218007³) is 545763506942741657683719023046343
• The square root of 81721218007 is 285869.2323545855
• The cube root of 81721218007 is 4339.5524680105

Scales and comparisons

• 81,721,218,007 seconds is equal to 2,598 years, 25 weeks, 10 hours, 20 minutes, 7 seconds.
• To count from 1 to 81,721,218,007 would take you about five thousand, one hundred ninety-six 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 81721218007 cubic inches would be around 361.6 feet tall.

Recreational maths with 81721218007

• 81721218007 backwards is 70081212718
• The number of decimal digits it has is: 11
• The sum of 81721218007's digits is 37
• More coming soon!