关于数论函数若干不等式的一个注记

A note for some inequalities for arithmetical function

改进与数论函数σ（ｎ）（整数ｎ的所有正因数的和）及Ｅｕｌｅｒ函数φ（ｎ）有关的几个不等式，并对不等式σ（ｎ）φ（ｎ）＜ｎｎ＜φ（ｎ）σ（ｎ）（ｎ∈Ｚ且ｎ≥７）给出了一个较为简便的证明。

Some inequalities for arithmetical function σ(n) , the sum of positive factor for integer n and Euler function φ(n) were improved, and a simpler proof was given to inequality σ(n) φ(n) <n n<φ(n) σ(n) (n∈ Z 且n≥7).