The radical of an integer is its largest square-free factor. An integer is square-free if and only if it is equal to its radical.
Any arbitary positive integer n can be represented in a unique way as the product of a powerful number and a square-free integer, which are coprime. The square-free factor is the largest square-free divisor k of n that is coprime with n/k.
Any arbitary positive integer n can be represented in a unique way as the product of a square and a square-free integer :
{displaystyle n=m^{2}k} {displaystyle n=m^{2}k}
In this factorization, m is the largest divisor of n such that m2 is a divisor of n.