# Sigma Function of Square-Free Integer/Examples

## Examples of $\sigma$ of Square-Free Integer

Let $\sigma: \Z_{>0} \to \Z_{>0}$ denote the $\sigma$ function: the sum of all the positive integer divisors of $n$.

### $\sigma$ of $66$

$\sigma \left({66}\right) = 144$

### $\sigma$ of $70$

$\sigma \left({70}\right) = 144$

### $\sigma$ of $110$

$\sigma \left({110}\right) = 216$

### $\sigma$ of $170$

$\map \sigma {170} = 324$