81315440

Names of 81315440

• Cardinal: 81315440 can be written as Eighty-one million, three hundred fifteen thousand, four hundred forty.

Scientific notation

• Scientific notation: 8.131544 × 10⁷

Factors of 81315440

• Number of distinct prime factors ω(n): 5
• Total number of prime factors Ω(n): 8
• Sum of prime factors: 964

Divisors of 81315440

• Number of divisors d(n): 80
• Complete list of divisors:
  1 2 4 5 8 10 16 19 20 38 40 61 76 80 95 122 152 190 244 304 305 380 488 610 760 877 976 1159 1220 1520 1754 2318 2440 3508 4385 4636 4880 5795 7016 8770 9272 11590 14032 16663 17540 18544 23180 33326 35080 46360 53497 66652 70160 83315 92720 106994 133304 166630 213988 266608 267485 333260 427976 534970 666520 855952 1016443 1069940 1333040 2032886 2139880 4065772 4279760 5082215 8131544 10164430 16263088 20328860 40657720 81315440
• Sum of all divisors σ(n): 202501920
• Sum of proper divisors (its aliquot sum) s(n): 121186480
• 81315440 is an abundant number, because the sum of its proper divisors (121186480) is greater than itself. Its abundance is 39871040

Bases of 81315440

• Binary: 100110110001100011001110000₂
• Hexadecimal: 0x4D8C670
• Base-36: 1CEVE8

Squares and roots of 81315440

• 81315440 squared (81315440²) is 6612200782393600
• 81315440 cubed (81315440³) is 537674015988679837184000
• The square root of 81315440 is 9017.5074161323
• The cube root of 81315440 is 433.2358018501

Scales and comparisons

• 81,315,440 seconds is equal to 2 years, 30 weeks, 3 days, 3 hours, 37 minutes, 20 seconds.
• To count from 1 to 81,315,440 would take you about three 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 81315440 cubic inches would be around 36.1 feet tall.

Recreational maths with 81315440

• 81315440 backwards is 04451318
• The number of decimal digits it has is: 8
• The sum of 81315440's digits is 26
• More coming soon!