Divisor Sum of Square-Free Integer/Examples/170

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Example of Divisor Sum of Square-Free Integer

$\map {\sigma_1} {170} = 324$

where $\sigma_1$ denotes the divisor sum.

Proof

We have that:

$170 = 2 \times 5 \times 17$


Hence:

\(\ds \map {\sigma_1} {170}\) \(=\) \(\ds \paren {2 + 1} \paren {5 + 1} \paren {17 + 1}\) Divisor Sum of Square-Free Integer
\(\ds \) \(=\) \(\ds 3 \times 6 \times 18\)
\(\ds \) \(=\) \(\ds 3 \times \paren {2 \times 3} \times \paren {2 \times 3^2}\)
\(\ds \) \(=\) \(\ds 2^2 \times 3^4\)
\(\ds \) \(=\) \(\ds \paren {2 \times 3^2}^2\)
\(\ds \) \(=\) \(\ds 18^2\)
\(\ds \) \(=\) \(\ds 324\)

$\blacksquare$