20981

Names of 20981

• Cardinal: 20981 can be written as Twenty thousand, nine hundred eighty-one.

Scientific notation

• Scientific notation: 2.0981 × 10⁴

Factors of 20981

• Number of distinct prime factors ω(n): 1
• Total number of prime factors Ω(n): 1
• Sum of prime factors: 20981

Divisors of 20981

• Number of divisors d(n): 2
• Complete list of divisors:
  1 20981
• Sum of all divisors σ(n): 20982
• Sum of proper divisors (its aliquot sum) s(n): 1
• 20981 is a deficient number, because the sum of its proper divisors (1) is less than itself. Its deficiency is 20980

Bases of 20981

• Binary: 101000111110101₂
• Hexadecimal: 0x51F5
• Base-36: G6T

Squares and roots of 20981

• 20981 squared (20981²) is 440202361
• 20981 cubed (20981³) is 9235885736141
• The square root of 20981 is 144.8481963989
• The cube root of 20981 is 27.5809186881

Scales and comparisons

• 20,981 seconds is equal to 5 hours, 49 minutes, 41 seconds.
• To count from 1 to 20,981 would take you about five hours.

  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 20981 cubic inches would be around 2.3 feet tall.

Recreational maths with 20981

• 20981 backwards is 18902
• 20981 is a twin prime! Its twin is 20983
• The number of decimal digits it has is: 5
• The sum of 20981's digits is 20
• More coming soon!