21491

Names of 21491

• Cardinal: 21491 can be written as Twenty-one thousand, four hundred ninety-one.

Scientific notation

• Scientific notation: 2.1491 × 10⁴

Factors of 21491

• Number of distinct prime factors ω(n): 1
• Total number of prime factors Ω(n): 1
• Sum of prime factors: 21491

Divisors of 21491

• Number of divisors d(n): 2
• Complete list of divisors:
  1 21491
• Sum of all divisors σ(n): 21492
• Sum of proper divisors (its aliquot sum) s(n): 1
• 21491 is a deficient number, because the sum of its proper divisors (1) is less than itself. Its deficiency is 21490

Bases of 21491

• Binary: 101001111110011₂
• Hexadecimal: 0x53F3
• Base-36: GKZ

Squares and roots of 21491

• 21491 squared (21491²) is 461863081
• 21491 cubed (21491³) is 9925899473771
• The square root of 21491 is 146.5980900283
• The cube root of 21491 is 27.8026083159

Scales and comparisons

• 21,491 seconds is equal to 5 hours, 58 minutes, 11 seconds.
• To count from 1 to 21,491 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 21491 cubic inches would be around 2.3 feet tall.

Recreational maths with 21491

• 21491 backwards is 19412
• 21491 is a twin prime! Its twin is 21493
• The number of decimal digits it has is: 5
• The sum of 21491's digits is 17
• More coming soon!