Notation for an integer being square-free

Question

An integer $n \neq 0$ is square-free if $n$ is divisible by no prime square. Can you figure out any notation for simplifying this long description?

It may be guessed that $p^{2} \nmid n$ for any prime $p$ is okay, but this is still a bit long.

Answer 1

Well, we could use $\mu(n)\ne 0$. Here $\mu$ is the Möbius function. I prefer (by a lot) to say square-free.

Answer 2

$n=ab$ implies $gcd(a,b)=1$ for all $a,b$.