81221381904

Names of 81221381904

• Cardinal: 81221381904 can be written as Eighty-one billion, two hundred twenty-one million, three hundred eighty-one thousand, nine hundred four.

Scientific notation

• Scientific notation: 8.1221381904 × 10¹⁰

Factors of 81221381904

• Number of distinct prime factors ω(n): 5
• Total number of prime factors Ω(n): 8
• Sum of prime factors: 2133890

Divisors of 81221381904

• Number of divisors d(n): 80
• Complete list of divisors:
  1 2 3 4 6 8 12 13 16 24 26 39 48 52 61 78 104 122 156 183 208 244 312 366 488 624 732 793 976 1464 1586 2379 2928 3172 4758 6344 9516 12688 19032 38064 2133811 4267622 6401433 8535244 12802866 17070488 25605732 27739543 34140976 51211464 55479086 83218629 102422928 110958172 130162471 166437258 221916344 260324942 332874516 390487413 443832688 520649884 665749032 780974826 1041299768 1331498064 1561949652 1692112123 2082599536 3123899304 3384224246 5076336369 6247798608 6768448492 10152672738 13536896984 20305345476 27073793968 40610690952 81221381904
• Sum of all divisors σ(n): 229666453184
• Sum of proper divisors (its aliquot sum) s(n): 148445071280
• 81221381904 is an abundant number, because the sum of its proper divisors (148445071280) is greater than itself. Its abundance is 67223689376

Bases of 81221381904

• Binary: 1001011101001001010111110111100010000₂
• Hexadecimal: 0x12E92BEF10
• Base-36: 11B943DC

Squares and roots of 81221381904

• 81221381904 squared (81221381904²) is 6596912878395418665216
• 81221381904 cubed (81221381904³) is 535810380283570210131478656651264
• The square root of 81221381904 is 284993.6523924699
• The cube root of 81221381904 is 4330.6869518329

Scales and comparisons

• 81,221,381,904 seconds is equal to 2,582 years, 30 weeks, 4 days, 6 hours, 58 minutes, 24 seconds.
• To count from 1 to 81,221,381,904 would take you about five thousand, one hundred sixty-five 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 81221381904 cubic inches would be around 360.9 feet tall.

Recreational maths with 81221381904

• 81221381904 backwards is 40918312218
• 81221381904 is a Harshad number.
• The number of decimal digits it has is: 11
• The sum of 81221381904's digits is 39
• More coming soon!