A note on necessary conditions for a friend of 10
Abstract
Solitary numbers are shrouded with mystery. A folklore conjecture assert that 10 is a solitary number i.e. it has no friends. In this article, we establish that if is a friend of then it must be odd square with at least seven distinct prime factors, with being the least one. Moreover there exists a prime factor of such that and where is the smallest odd positive integer greater than and less than or equal to , provided . Further, there exist prime factors and (not necessarily distinct) of such that and . Besides, we prove that if a Fermat prime divides then must have a prime factor congruent to modulo . Also, if we consider the form of as then is non square-free. Furthermore, we show that and if then where and denote the total number of prime factors and the number of distinct prime factors of the integer respectively.
Cite
@article{arxiv.2404.00624,
title = {A note on necessary conditions for a friend of 10},
author = {Tapas Chatterjee and Sagar Mandal and Sourav Mandal},
journal= {arXiv preprint arXiv:2404.00624},
year = {2025}
}