The number of preimages of iterates of $φ$ and $σ$

Agbolade Patrick Akande

Published 2024-01-08Version 1

Paul Erdos and Carl Pomerance have proofs on an asymptotic upper bound on the number of preimages of Euler's totient function $\phi$ and the sum-of-divisors functions $\sigma$. In this paper, we will extend the upper bound to the number of preimages of iterates of $\phi$ and $\sigma$. Using these new asymptotic upper bounds, a conjecuture in Konick and Katai's paper, "On the uniform distribution of certain sequences involving the Euler totient function and the sum of divisors function" is now proven and many corollaries follow from their proven conjecture.