Part of the Computing fundamentals glossary:

The factorial, symbolized by an exclamation mark (!), is a quantity defined for all integer s greater than or equal to 0.

For an integer n greater than or equal to 1, the factorial is the product of all integers less than or equal to n but greater than or equal to 1. The factorial value of 0 is defined as equal to 1. The factorial values for negative integers are not defined.

Mathematically, the formula for the factorial is as follows. If n is an integer greater than or equal to 1, then

n ! = n ( n - 1)( n - 2)( n - 3) ... (3)(2)(1)

If p = 0, then p ! = 1 by convention.

The factorial is of interest to number theorists. It often arises in probability calculations, particularly those involving combinations and permutations. The factorial also arises occasionally in calculus and physics.

Compare double factorial .

This was last updated in September 2005
Posted by: Margaret Rouse

Related Terms

Definitions

  • Schrodinger's cat

    - Schrodinger's cat explained: This definition describes Schrodinger's famous thought experiment and its place in quantum theory. (WhatIs.com)

  • flash storage

    - Flash storage, based on flash memory, is used for data repositories, storage systems and consumer devices, such as USB drives, smartphones and solid-state drives. Flash-based storage is faster than... (WhatIs.com)

  • six degrees of separation

    - Six degrees of separation is the theory that anyone on the planet can be connected to any other person on the planet through a chain of acquaintances that has no more than five intermediaries. (WhatIs.com)

Glossaries

  • Computing fundamentals

    - Terms related to computer fundamentals, including computer hardware definitions and words and phrases about software, operating systems, peripherals and troubleshooting.

  • Internet applications

    - This WhatIs.com glossary contains terms related to Internet applications, including definitions about Software as a Service (SaaS) delivery models and words and phrases about web sites, e-commerce ...

Ask a Question. Find an Answer.Powered by ITKnowledgeExchange.com

Ask An IT Question

Get answers from your peers on your most technical challenges

Ask Question

Tech TalkComment

Share
Comments

    Results

    Contribute to the conversation

    All fields are required. Comments will appear at the bottom of the article.