composite number

composite number (plural composite numbers)

1. (number theory) A (nonzero) natural number that is expressible as the product of two (or more) natural numbers other than itself and 1.
   • 1853, Edward Hinkley, Tables of the Prime Numbers and Prime Factors of the Composite Numbers from 1 to 100,000, page 13:

     It is evident, moreover, that if a composite number terminates in any one of the digits 1, 3, 7, 9, no one of its factors can be the number 5, or any number ending in 5.

   • 1994, Hans Riesel, Prime Numbers and Computer Methods for Factorization, 2nd edition, Springer (Birkhäuser), →ISBN, page 91:

     The above remark applies also to many composite numbers which are not Carmichael numbers, but which are still not shown to be composite by Fermat's theorem for a specific base a. […] Therefore, using Euler's criterion or a strong primality test with enough bases will finally reveal any composite number or, alternatively, prove the primality of any prime N.

   • 2006, Sze Kui Ng, Quantum Invariant of 3-Manifolds, Samuel F. Neilson (editor), New Research on Three-manifolds and Mathematics, Nova Science Publishers, page 47,

     It is interesting that in each interval composite numbers are one-to-one assigned to the comparable composite knots while prime numbers are one-to-one assigned to prime knots.

• prime number

• natural number, integer, number

• highly composite number, semiprime

• Canonical representation of a positive integer on Wikipedia.Wikipedia
• Integer factorization on Wikipedia.Wikipedia
• Sieve of Eratosthenes on Wikipedia.Wikipedia
• Table of prime factors on Wikipedia.Wikipedia
• Lists of Composites and Composite Generators with Prime Factors