How to check if a number is power of a prime number?

How to check if a number is power of a prime number?

e.g. 9, 25, 27, 36 are powers of a prime number. Program should return logical 1 for these kinds of numbers.

[Torsten]

A Google search gives this algorithm:

https://www.geeksforgeeks.org/check-if-the-number-is-a-prime-power-number/