deficient number

noun

, Mathematics.

1. a positive number that is greater than the sum of all positive integers that are submultiples of it, as 10, which is greater than the sum of 1, 2, and 5.

Word History and Origins

Origin of deficient number¹

First recorded in 1720–30

Example Sentences

This is opposed to a deficient number, as 14, whose aliquot parts are 1, 2, 7, the sum of which is 10; and to a perfect number, which is equal to the sum of its aliquot parts, as 6, whose aliquot parts are 1, 2.,

From Project Gutenberg