On the small prime factors of a non-deficient number

Autor: Zelinsky, Joshua
Rok vydání: 2020
Předmět:
Druh dokumentu: Working Paper
Popis: Let $\sigma(n)$ to be the sum of the positive divisors of $n$. A number is non-deficient if $\sigma(n) \geq 2n$. We establish new lower bounds for the number of distinct prime factors of an odd non-deficient number in terms of its second smallest, third smallest and fourth smallest prime factors. We also obtain tighter bounds for odd perfect numbers. We also discuss the behavior of $\sigma(n!+1)$, $\sigma(2^n+1)$, and related sequences.
Comment: 19 pages. Accepted to Integers
Databáze: arXiv