Definition:Almost Perfect Number

Definition
Let $n \in \Z_{\ge 0}$ be a positive integer.

Definition 3
Thus an almost perfect number can be described as "deficient, but only just".

Also known as
An almost perfect number is also known as:
 * a least deficient number
 * a slightly defective number.

Some sources hyphenate: almost-perfect.

Also see

 * Equivalence of Definitions of Almost Perfect Number


 * Definition:Perfect Number
 * Definition:Quasiperfect Number
 * Definition:Abundance


 * Power of 2 is Almost Perfect