Eighty One

+**Eighty One** (81) is the natural number following eighty and preceding eighty-two. As a [composite number](/wiki/Composite_Number), it is notably a perfect square, being the square of [nine](/wiki/Nine). This number finds relevance in mathematical properties and various symbolic contexts.

+## See also

+- [Number Theory](/wiki/Number_Theory)

+- [Perfect Square](/wiki/Perfect_Square)

+- [Eighty](/wiki/Eighty)