perfect number: Meaning and Definition of

per'fect num'ber

Pronunciation: [key]
— Math. Math.
  1. a positive number that is equal to the sum of all positive integers that are submultiples of it, as 6, which is equal to the sum of 1, 2, and 3. Cf.
Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease.