The distribution functions of $σ(n)/n$ and $n/φ(n)$, II

Andreas Weingartner

Published 2010-11-18Version 1

Let $\sigma(n)$ be the sum of the positive divisors of $n$, and let $A(t)$ be the natural density of the set of positive integers $n$ satisfying $\sigma(n)/n \ge t$. We give an improved asymptotic result for $\log A(t)$ as $t$ grows unbounded. The same result holds if $\sigma(n)/n$ is replaced by $n/\phi(n)$, where $\phi(n)$ is Euler's totient function.