Divisor Sum of 265

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Example of Divisor Sum of Non-Square Semiprime

$\map {\sigma_1} {265} = 324$

where $\sigma_1$ denotes the divisor sum function.


Proof

We have that:

$265 = 5 \times 53$


Hence:

\(\ds \map {\sigma_1} {265}\) \(=\) \(\ds \paren {5 + 1} \paren {53 + 1}\) Divisor Sum of Non-Square Semiprime
\(\ds \) \(=\) \(\ds 6 \times 54\)
\(\ds \) \(=\) \(\ds \paren {2 \times 3} \times \paren {2 \times 3^3}\)
\(\ds \) \(=\) \(\ds 2^2 \times 3^4\)
\(\ds \) \(=\) \(\ds \paren {2 \times 3^2}^2\)
\(\ds \) \(=\) \(\ds 18^2\)
\(\ds \) \(=\) \(\ds 324\)

$\blacksquare$