Prime Number

Pronunciation: /praɪm ˈnʌm.bər/ Explain

A prime number is an integer that is evenly divisible only by 1 and itself. An example of a prime number is the integer 5. The only integers that divide evenly into 5 are 1 and 5. If we try to divide 5 by 2, we get 2 1/2, which is not an integer.

A composite number is an integer that is not prime. 6 is not a prime number. 6 is evenly divisible by both 2 and 3, so 6 is a composite number.


  1. McAdams, David E.. All Math Words Dictionary, prime number. 2nd Classroom edition 20150108-4799968. pg 144. Life is a Story Problem LLC. January 8, 2015. Buy the book

More Information

  • Malkevitch, Joseph. Primes. American Mathematical Society. 2/6/2010.

Cite this article as:

McAdams, David E. Prime Number. 12/21/2018. All Math Words Encyclopedia. Life is a Story Problem LLC.

Revision History

12/21/2018: Reviewed and corrected IPA pronunication. (McAdams, David E.)
12/1/2018: Removed broken links, updated license, implemented new markup. (McAdams, David E.)
9/3/2008: Expanded 'More Information'. (McAdams, David E.)
8/22/2007: Revised See Also to match current standard. (McAdams, David E.)
7/12/2007: Initial version. (McAdams, David E.)

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