Let $\displaystyle p$ be a prime number. Then how many generators of the cyclic group $\displaystyle Z_{p^r}$, with $\displaystyle r\in\mathbb{Z}$ and $\displaystyle r\ge 1$
Let $\displaystyle p$ be a prime number. Then how many generators of the cyclic group $\displaystyle Z_{p^r}$, with $\displaystyle r\in\mathbb{Z}$ and $\displaystyle r\ge 1$
$\displaystyle \mbox{An element}\,\,x\in Z_{p^r}\,\,\mbox{is a generator iff}\,\,(x,p^r)=1\,\,\mbox{, so there are....generators}$