21521

21,521 is a prime number. Like all primes greater than two, it is odd and has no factors apart from itself and one.

21521 is a prime number. Like all primes (except two), it is an odd number.

Prime factorization of 21521:

21521

See below for interesting mathematical facts about the number 21521 from the Numbermatics database.

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Names Factors Divisors Scales Roots Fun

Names of 21521

  • Cardinal: 21521 can be written as Twenty-one thousand, five hundred twenty-one.

Scientific notation

  • Scientific notation: 2.1521 × 104

Factors of 21521

  • Number of distinct prime factors ω(n): 1
  • Total number of prime factors Ω(n): 1
  • Sum of prime factors: 21521

Divisors of 21521

  • Number of divisors d(n): 2
  • Complete list of divisors:
  • Sum of all divisors σ(n): 21522
  • Sum of proper divisors (its aliquot sum) s(n): 1
  • 21521 is a deficient number, because the sum of its proper divisors (1) is less than itself. Its deficiency is 21520

Bases of 21521

  • Binary: 101010000010001 2
  • Hexadecimal: 0x5411
  • Base-36: GLT

Squares and roots of 21521

  • 21521 squared (215212) is 463153441
  • 21521 cubed (215213) is 9967525203761
  • The square root of 21521 is 146.7003749143
  • The cube root of 21521 is 27.8155391621

Scales and comparisons

How big is 21521?
  • 21,521 seconds is equal to 5 hours, 58 minutes, 41 seconds.
  • To count from 1 to 21,521 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.

    Note: we do not count involuntary pauses, bathroom breaks or the necessity of sleep in our calculation!

  • A cube with a volume of 21521 cubic inches would be around 2.3 feet tall.

Recreational maths with 21521

  • 21521 backwards is 12512
  • 21521 is a twin prime! Its twin is 21523
  • The number of decimal digits it has is: 5
  • The sum of 21521's digits is 11
  • More coming soon!

The information we have on file for 21521 includes mathematical data and numerical statistics calculated using standard algorithms and methods. We are adding more all the time. If there are any features you would like to see, please contact us. Information provided for educational use, intellectual curiosity and fun!

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