对于正整数k,设σ(k)是k的不同约数之和.运用初等数论方法确定了一个关于σ(k)的不等式中的最佳常数.
For any positive integer k, let σ(k) denote the sum of distinct divisors of k. With some elementary number theory methods, the best constant of an inequality on σ(k) is determined.