21397791

Names of 21397791

• Cardinal: 21397791 can be written as Twenty-one million, three hundred ninety-seven thousand, seven hundred ninety-one.

Scientific notation

• Scientific notation: 2.1397791 × 10⁷

Factors of 21397791

• Number of distinct prime factors ω(n): 3
• Total number of prime factors Ω(n): 3
• Sum of prime factors: 10541

Divisors of 21397791

• Number of divisors d(n): 8
• Complete list of divisors:
  1 3 727 2181 9811 29433 7132597 21397791
• Sum of all divisors σ(n): 28572544
• Sum of proper divisors (its aliquot sum) s(n): 7174753
• 21397791 is a deficient number, because the sum of its proper divisors (7174753) is less than itself. Its deficiency is 14223038

Bases of 21397791

• Binary: 1010001101000000100011111₂
• Hexadecimal: 0x146811F
• Base-36: CQMN3

Squares and roots of 21397791

• 21397791 squared (21397791²) is 457865459679681
• 21397791 cubed (21397791³) is 9797309412344740984671
• The square root of 21397791 is 4625.7746378309
• The cube root of 21397791 is 277.6235566981

Scales and comparisons

• 21,397,791 seconds is equal to 35 weeks, 2 days, 15 hours, 49 minutes, 51 seconds.
• To count from 1 to 21,397,791 would take you about eleven 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 21397791 cubic inches would be around 23.1 feet tall.

Recreational maths with 21397791

• 21397791 backwards is 19779312
• The number of decimal digits it has is: 8
• The sum of 21397791's digits is 39
• More coming soon!