# Math Help - number of incongruent primitive roots

1. ## number of incongruent primitive roots

determine the number of incongruent primitive roots. Find all such primitive roots.

For 18:

2. Originally Posted by mndi1105
determine the number of incongruent primitive roots. Find all such primitive roots.

For 18:
If $a$ is primitive root of $18$ then $a^k$ is a primitive root if $\gcd(k,\phi(18))=1$. With that you can find all primitive roots.