Lower bounds on expressions depending on the functions {\boldmath$\varphi(n)$}, {\boldmath$ψ(n)$} and {\boldmath$σ(n)$}, III

Abstract

This work is concerned with the study of lower bounds for various expressions related to the arithmetic functions $\varphi(n)$, $ψ(n)$ and $σ(n)$. Several explicit estimates are established.