Squarefree part
= Squarefree part
{title2=$\operatorname{sf}(n)=\prod_{v_p(n)\text{ odd}}p$}
= Squarefree core
{synonym}
The squarefree part of a <positive integer> $n$ is the unique <squarefree integer> $s$ such that $n=s t^2$ for a <positive integer> $t$. For example, the squarefree part of $72=2^3 3^2$ is $2$. It retains precisely the <primes> with odd <prime exponents>; the <radical of an integer> instead retains every distinct <prime factor>.