Show that if is a number having primitive roots, then the product of the positive integers less than or equal to and relatively prime to is congruent to .

has primitive roots means there is a least residue such that

Since is a primitive root of , then the least residues of are a permutation of the positive integers less than and relatively prime to .

So the congruency to look at is correct??? I have been looking at this congruency and failing to make it true.

Thanks for any help.