Divisor Sum of 29,925

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Example of Divisor Sum of Integer

$\map {\sigma_1} {29 \, 925} = 64 \, 480$

where $\sigma_1$ denotes the divisor sum function.


Proof

We have that:

$29 \, 925 = 3^2 \times 5^2 \times 7 \times 19$


Hence:

\(\ds \map {\sigma_1} {29 \, 925}\) \(=\) \(\ds \dfrac {3^3 - 1} {3 - 1} \times \dfrac {5^3 - 1} {5 - 1} \times \paren {7 + 1} \times \paren {19 + 1}\) Divisor Sum of Integer
\(\ds \) \(=\) \(\ds \dfrac {26} 2 \times \dfrac {124} 4 \times 8 \times 20\)
\(\ds \) \(=\) \(\ds 13 \times 31 \times 8 \times 20\)
\(\ds \) \(=\) \(\ds 13 \times 31 \times 2^3 \times \paren {2^2 \times 5}\)
\(\ds \) \(=\) \(\ds 2^5 \times 5 \times 13 \times 31\)
\(\ds \) \(=\) \(\ds 64 \, 480\)

$\blacksquare$