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

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

Prime factorization of 11:


See below for interesting mathematical facts about the number 11 from the Numbermatics database.

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Names Factors Divisors Scales Roots Fun

Names of 11

  • Cardinal: 11 can be written as Eleven.

Scientific notation

  • Scientific notation: 1.1 × 101

Factors of 11

  • Number of distinct prime factors ω(n): 1
  • Total number of prime factors Ω(n): 1
  • Sum of prime factors: 11

Divisors of 11

  • Number of divisors d(n): 2
  • Complete list of divisors:
    1 11
  • Sum of all divisors σ(n): 12
  • Sum of proper divisors (its aliquot sum) s(n): 1
  • 11 is a deficient number, because the sum of its proper divisors (1) is less than itself. Its deficiency is 10

Bases of 11

  • Binary: 1011 2
  • Hexadecimal: 0xb

Squares and roots of 11

  • 11 squared (112) is 121
  • 11 cubed (113) is 1331
  • The square root of 11 is 3.3166247901
  • The cube root of 11 is 2.2239800905

Scales and comparisons

How big is 11?
  • To count from 1 to 11 would take you about five seconds.

    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 11 cubic inches would be around 0.2 feet tall.

Recreational maths with 11

  • 11 is the same when its digits are reversed! That makes it a palindromic prime number.
  • 11 is a twin prime! Its twin is 13
  • The number of decimal digits it has is: 2
  • The sum of 11's digits is 2
  • More coming soon!

The information we have on file for 11 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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