21821

Names of 21821

• Cardinal: 21821 can be written as Twenty-one thousand, eight hundred twenty-one.

Scientific notation

• Scientific notation: 2.1821 × 10⁴

Factors of 21821

• Number of distinct prime factors ω(n): 1
• Total number of prime factors Ω(n): 1
• Sum of prime factors: 21821

Divisors of 21821

• Number of divisors d(n): 2
• Complete list of divisors:
  1 21821
• Sum of all divisors σ(n): 21822
• Sum of proper divisors (its aliquot sum) s(n): 1
• 21821 is a deficient number, because the sum of its proper divisors (1) is less than itself. Its deficiency is 21820

Bases of 21821

• Binary: 101010100111101₂
• Hexadecimal: 0x553D
• Base-36: GU5

Squares and roots of 21821

• 21821 squared (21821²) is 476156041
• 21821 cubed (21821³) is 10390200970661
• The square root of 21821 is 147.7193284577
• The cube root of 21821 is 27.9441915599

Scales and comparisons

• 21,821 seconds is equal to 6 hours, 3 minutes, 41 seconds.
• To count from 1 to 21,821 would take you about six 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 21821 cubic inches would be around 2.3 feet tall.

Recreational maths with 21821

• 21821 backwards is 12812
• The number of decimal digits it has is: 5
• The sum of 21821's digits is 14
• More coming soon!