861 is an odd composite number composed of three prime numbers multiplied together.

861 is an odd composite number. It is composed of three distinct prime numbers multiplied together. It has a total of eight divisors.

Prime factorization of 861:

3 × 7 × 41

See below for interesting mathematical facts about the number 861 from the Numbermatics database.

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Names Factors Divisors Scales Roots Fun

Names of 861

  • Cardinal: 861 can be written as Eight hundred sixty-one.

Scientific notation

  • Scientific notation: 8.61 × 102

Factors of 861

  • Number of distinct prime factors ω(n): 3
  • Total number of prime factors Ω(n): 3
  • Sum of prime factors: 51

Divisors of 861

  • Number of divisors d(n): 8
  • Complete list of divisors:
  • Sum of all divisors σ(n): 1344
  • Sum of proper divisors (its aliquot sum) s(n): 483
  • 861 is a deficient number, because the sum of its proper divisors (483) is less than itself. Its deficiency is 378

Bases of 861

  • Binary: 1101011101 2
  • Hexadecimal: 0x35D
  • Base-36: NX

Squares and roots of 861

  • 861 squared (8612) is 741321
  • 861 cubed (8613) is 638277381
  • The square root of 861 is 29.3428015023
  • The cube root of 861 is 9.5133699099

Scales and comparisons

How big is 861?
  • 861 seconds is equal to 14 minutes, 21 seconds.
  • To count from 1 to 861 would take you about seven 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 861 cubic inches would be around 0.8 feet tall.

Recreational maths with 861

  • 861 backwards is 168
  • The number of decimal digits it has is: 3
  • The sum of 861's digits is 15
  • More coming soon!

The information we have on file for 861 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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