composite number

A composite numberMathworldPlanetmath is a positive integer which is not prime and not equal to 1. That is, n is composite if n=ab, with a and b natural numbers both not equal to 1.


  • 1 is not composite (and also not prime), by definition.

  • 2 is not composite, as it is prime.

  • 15 is composite, since 15=35.

  • 93555 is composite, since 93555=355711.

  • 52223 is not composite, since it is prime.

More generally, we can define compositeness any time there is an ambient notion of an irreducible elementMathworldPlanetmath. In an integral domainMathworldPlanetmath, for example, an element is said to be composite if it neither zero, a unit, nor irreducible.

Title composite number
Canonical name CompositeNumber
Date of creation 2013-03-22 12:39:37
Last modified on 2013-03-22 12:39:37
Owner mathcam (2727)
Last modified by mathcam (2727)
Numerical id 9
Author mathcam (2727)
Entry type Definition
Classification msc 11A41
Synonym composite