Positive rational number of the form $\phi (k{m}^a)/\phi (l{n}^b)$

Hongjian Li, Pingzhi Yuan, Hairong Bai

Let $k,l,a$ and $b$ be positive integers with $\max \{a,b\}\ge 2$. In this paper, we show that every positive rational number can be written as the form $\phi (k{m}^a)/\phi (l{n}^b)$,…