Meaning of prime number

prime' num'ber

Pronunciation: [key]
— Math. Math.
  1. a positive integer that is not divisible without remainder by any integer except itself and 1, with 1 often excluded:Also called The integers 2, 3, 5, and 7 are prime numbers.
Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease.