Editing Unitary perfect number (section)

{{Short description|Integer which is the sum of its positive unitary divisors, not including itself}}
{{unsolved|mathematics|Are there infinitely many unitary perfect numbers?}}
A '''unitary perfect number''' is an [[integer]] which is the sum of its positive [[proper divisor|proper]] [[unitary divisor]]s, not including the number itself. (A [[divisor]] ''d'' of a number ''n'' is a unitary divisor if ''d'' and ''n''/''d'' share no common [[divisor|factors]]). The number 6 is the only  number that is both a [[perfect number]] and a unitary perfect number.