18999981

Names of 18999981

• Cardinal: 18999981 can be written as Eighteen million, nine hundred ninety-nine thousand, nine hundred eighty-one.

Scientific notation

• Scientific notation: 1.8999981 × 10⁷

Factors of 18999981

• Number of distinct prime factors ω(n): 6
• Total number of prime factors Ω(n): 8
• Sum of prime factors: 90

Divisors of 18999981

• Number of divisors d(n): 128
• Complete list of divisors:
  1 3 7 9 11 13 19 21 27 33 37 39 57 63 77 91 99 111 117 133 143 171 189 209 231 247 259 273 297 333 351 399 407 429 481 513 627 693 703 741 777 819 999 1001 1197 1221 1287 1443 1463 1729 1881 2079 2109 2223 2331 2457 2717 2849 3003 3367 3591 3663 3861 4329 4389 4921 5187 5291 5643 6327 6669 6993 7733 8151 8547 9009 9139 10101 10989 12987 13167 14763 15561 15873 18981 19019 23199 24453 25641 27027 27417 30303 37037 39501 44289 46683 47619 54131 57057 63973 69597 73359 76923 82251 90909 100529 111111 132867 142857 162393 171171 191919 208791 246753 301587 333333 487179 513513 575757 703703 904761 999999 1461537 1727271 2111109 2714283 6333327 18999981
• Sum of all divisors σ(n): 40857600
• Sum of proper divisors (its aliquot sum) s(n): 21857619
• 18999981 is an abundant number, because the sum of its proper divisors (21857619) is greater than itself. Its abundance is 2857638

Bases of 18999981

• Binary: 1001000011110101010101101₂
• Hexadecimal: 0x121EAAD
• Base-36: BB8H9

Squares and roots of 18999981

• 18999981 squared (18999981²) is 360999278000361
• 18999981 cubed (18999981³) is 6858979423020576993141
• The square root of 18999981 is 4358.8967640907
• The cube root of 18999981 is 266.8400759255

Scales and comparisons

• 18,999,981 seconds is equal to 31 weeks, 2 days, 21 hours, 46 minutes, 21 seconds.
• To count from 1 to 18,999,981 would take you about forty-seven weeks!

  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 18999981 cubic inches would be around 22.2 feet tall.

Recreational maths with 18999981

• 18999981 is the same when its digits are reversed! That makes it a palindromic number.
• The number of decimal digits it has is: 8
• The sum of 18999981's digits is 54
• More coming soon!