Robin's inequality for new families of integers

Abstract

Robin's criterion states that the Riemann Hypothesis (RH) is true if and only if Robin's inequality $σ(n):=\sum_{p|n}p 5040$, where $γ$ denotes the Euler-Mascheroni constant. We show that if the 2-adic order of n is big enough in comparison to the odd part of n then Robin's inequality is satisfied. We also show that if an positive integer $n$ satisfies either $ν_2(n) \leq 19$, $ν_3(n) \leq 12$,$ν_5(n) \leq 7$, $ν_7(n) \leq 6$, $ν_{11}(n) \leq 5$ then Robin's inequality is satisfied, where $ν_p(n)$ is the p-adic order of $n$. In the end we show that $σ(n)/n < 1.0000005645 e^γ\log \log n$ holds unconditionally for $n > 5040$.