Quasiperfect number

This article defines a property that can be evaluated for a natural number, i.e., every natural number either satisfies the property or does not satisfy the property.
View a complete list of properties of natural numbers

Definition

A quasiperfect number is a natural number that is the sum of all its proper nontrivial divisors. In other words, it is a natural number $n$ such that $\sigma (n)=2n+1$.

Relation with other properties

Weaker properties

• Pseudoperfect number
• Abundant number