# Euler's totient function relative function

For the $\sigma$ function, the ratio $\sigma(m)/m$ is known as the abundancy index. Is there any special name for $\phi(m)/m$ with $\phi$ the Euler's totient function ?

I called it $\pi^{-1}(m)$ in a number theory article I posted on the ArXiv. I did not scour the literature, but I conjecture that Erdos never came up with a name for it (he didn't in the papers I saw that talked about the quantity), and I would also like to know if anyone else did.
• Also, while there may be a relation between $\pi(x)$ and $\pi^{-1}(m)$, I never planned to use the two in the same article. Gerhard "Like Edward Teller And Anti-Teller" Paseman, 2015.09.02 – Gerhard Paseman Sep 2 '15 at 16:44