Factorial

usgb/fækˈtɔːriəl/
noun

The factorial of a number is a product of all integers from 1 to that number. It's often used in calculations of probability.

The factorial of 5 is 120 because 5*4*3*2*1 equals 120.
Visual representation of "factorial" - The factorial of a number is a product of all integers from 1 to that number. It's often used in calculations of probability.

Often appears as...

  • factorial of a number
  • calculate the factorial

Usage tips

Technical

Definition 1 of 2
Visual representation of "factorial"
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Math Specific

Used mostly in math, particularly in probability and combinatorics.

Illustration for Math Specific
To solve this problem, you'll need to find the factorial of 7.
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Symbol Representation

The exclamation mark (!) denotes factorial, like in 5! for 5 factorial.

Illustration for Symbol Representation
Can you calculate 8! for me?
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Non-Negative Integers

Factorials are only defined for non-negative integers, and 0! is 1.

Illustration for Non-Negative Integers
Remember that the factorial of a negative number doesn't exist.
Visual representation of the word "Factorial"

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