1 is an odd number which is unique. It's the only number which is neither prime nor composite. One is known as the multiplicative identity or unit.

1 is an odd number which is uniquely neither prime nor composite. It is known as the multiplicative identity or unit. It's also the only positive number with no other divisors.

Prime factorization of 1:


See below for interesting mathematical facts about the number 1 from the Numbermatics database.

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Names Factors Divisors Scales Roots Fun

Names of 1

  • Cardinal: 1 can be written as One.

Scientific notation

  • Scientific notation: 1 × 100

Factors of 1

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

Divisors of 1

  • Number of divisors d(n): 1
  • Complete list of divisors:
  • Sum of all divisors σ(n): 1
  • Sum of proper divisors (its aliquot sum) s(n): 0
  • 1 is a deficient number, because the sum of its proper divisors (0) is less than itself. Its deficiency is 1

Bases of 1

  • Binary: 1 2
  • Hexadecimal: 0x1

Squares and roots of 1

  • 1 squared (12) is 1
  • 1 cubed (13) is 1
  • 1 is a perfect square number. Its square root is 1
  • 1 is a perfect cube number. Its cube root is 1

Scales and comparisons

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

    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 1 cubic inches would be around 0.1 feet tall.

Recreational maths with 1

  • 1 is the same when its digits are reversed! That makes it a palindromic number.
  • 1 is a Harshad number.
  • The number of decimal digits it has is: 1
  • The sum of 1's digits is 1
  • More coming soon!

The information we have on file for 1 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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