1981

Names of 1981

• Cardinal: 1981 can be written as One thousand, nine hundred eighty-one.

Scientific notation

• Scientific notation: 1.981 × 10³

Factors of 1981

• Number of distinct prime factors ω(n): 2
• Total number of prime factors Ω(n): 2
• Sum of prime factors: 290

Divisors of 1981

• Number of divisors d(n): 4
• Complete list of divisors:
  1 7 283 1981
• Sum of all divisors σ(n): 2272
• Sum of proper divisors (its aliquot sum) s(n): 291
• 1981 is a deficient number, because the sum of its proper divisors (291) is less than itself. Its deficiency is 1690

Bases of 1981

• Binary: 11110111101₂
• Hexadecimal: 0x7BD
• Base-36: 1J1

Squares and roots of 1981

• 1981 squared (1981²) is 3924361
• 1981 cubed (1981³) is 7774159141
• The square root of 1981 is 44.5084261685
• The cube root of 1981 is 12.5591859859

Scales and comparisons

• 1,981 seconds is equal to 33 minutes, 1 second.
• To count from 1 to 1,981 would take you about thirty-three minutes.

  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 1981 cubic inches would be around 1 feet tall.

Recreational maths with 1981

• 1981 backwards is 1891
• The number of decimal digits it has is: 4
• The sum of 1981's digits is 19
• More coming soon!