Article ID Journal Published Year Pages File Type
4593592 Journal of Number Theory 2015 16 Pages PDF
Abstract

Let ω(n)ω(n) (resp. Ω(n)Ω(n)) denote the number of prime divisors (resp. with multiplicity) of a natural number n  . In 1917, Hardy and Ramanujan proved that the normal order of ω(n)ω(n) is log⁡log⁡nlog⁡log⁡n, and the same is true of Ω(n)Ω(n); roughly speaking, a typical natural number n   has about log⁡log⁡nlog⁡log⁡n prime factors. We prove a similar result for ω(s(n))ω(s(n)), where s(n)s(n) denotes the sum of the proper divisors of n  : For all n≤xn≤x not belonging to a set of size o(x)o(x),|ω(s(n))−log⁡log⁡s(n)|<ϵlog⁡log⁡s(n),|ω(s(n))−log⁡log⁡s(n)|<ϵlog⁡log⁡s(n), and the same is true for Ω(s(n))Ω(s(n)).

Related Topics
Physical Sciences and Engineering Mathematics Algebra and Number Theory
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