Given $N, c$ such that $1 < c < N$. What is the following set?
$S=\{ k : 1 \leq k \leq N \text{ and } N \mid kc \}$
What can we say about this set?
For example, if $\gcd(c,N)=1,$ then we know $S=\{N\}$. what about more general case?
Given $N, c$ such that $1 < c < N$. What is the following set?
$S=\{ k : 1 \leq k \leq N \text{ and } N \mid kc \}$
What can we say about this set?
For example, if $\gcd(c,N)=1,$ then we know $S=\{N\}$. what about more general case?