400

400 is an even composite number composed of two prime numbers multiplied together.

400 is an even composite number. It is composed of two distinct prime numbers multiplied together. It has a total of fifteen divisors.

Prime factorization of 400:

24 × 52

(2 × 2 × 2 × 2 × 5 × 5)

See below for interesting mathematical facts about the number 400 from the Numbermatics database.

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Names Factors Divisors Scales Roots Fun

Names of 400

  • Cardinal: 400 can be written as Four hundred.

Scientific notation

  • Scientific notation: 4 × 102

Factors of 400

  • Number of distinct prime factors ω(n): 2
  • Total number of prime factors Ω(n): 6
  • Sum of prime factors: 7

Divisors of 400

  • Number of divisors d(n): 15
  • Complete list of divisors:
  • Sum of all divisors σ(n): 961
  • Sum of proper divisors (its aliquot sum) s(n): 561
  • 400 is an abundant number, because the sum of its proper divisors (561) is greater than itself. Its abundance is 161

Bases of 400

  • Binary: 110010000 2
  • Hexadecimal: 0x190
  • Base-36: B4

Squares and roots of 400

  • 400 squared (4002) is 160000
  • 400 cubed (4003) is 64000000
  • 400 is a perfect square number. Its square root is 20
  • The cube root of 400 is 7.3680629971

Scales and comparisons

How big is 400?
  • 400 seconds is equal to 6 minutes, 40 seconds.
  • To count from 1 to 400 would take you about three minutes.

    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 400 cubic inches would be around 0.6 feet tall.

Recreational maths with 400

  • 400 backwards is 004
  • 400 is a Harshad number.
  • The number of decimal digits it has is: 3
  • The sum of 400's digits is 4
  • More coming soon!

The information we have on file for 400 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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