factorial

[ fak-tawr-ee-uhl, -tohr- ]

noun
  1. Mathematics. the product of a given positive integer multiplied by all lesser positive integers: The quantity four factorial (4!) = 4 ⋅ 3 ⋅ 2 ⋅ 1 = 24. Symbol:n!, where n is the given integer.

adjective
  1. Mathematics. of or relating to factors or factorials.

  2. of or relating to a factor or a factory.

Origin of factorial

1
First recorded in 1810–20; factor + -ial

Other words from factorial

  • fac·to·ri·al·ly, adverb

Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2024

British Dictionary definitions for factorial

factorial

/ (fækˈtɔːrɪəl) maths /


noun
  1. the product of all the positive integers from one up to and including a given integer. Factorial zero is assigned the value of one: factorial four is 1 × 2 × 3 × 4 . Symbol: n !, where n is the given integer

adjective
  1. of or involving factorials or factors

Derived forms of factorial

  • factorially, adverb

Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Scientific definitions for factorial

factorial

[ făk-tôrē-əl ]


  1. The product of all of the positive integers from 1 to a given positive integer. It is written as the given integer followed by an exclamation point. For example, the factorial of 4 (written 4!) is 1 X 2 X 3 X 4, or 24.

The American Heritage® Science Dictionary Copyright © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.