Divisor Sum of 10,395
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Example of Divisor Sum of Integer
- $\map {\sigma_1} {10 \, 395} = 23 \, 040$
where $\sigma_1$ denotes the divisor sum function.
Proof
We have that:
- $10 \, 395 = 3^3 \times 5 \times 7 \times 11$
Hence:
\(\ds \map {\sigma_1} {10 \, 395}\) | \(=\) | \(\ds \dfrac {3^4 - 1} {3 - 1} \times \paren {5 + 1} \times \paren {7 + 1} \times \paren {11 + 1}\) | Divisor Sum of Integer | |||||||||||
\(\ds \) | \(=\) | \(\ds \dfrac {80} 2 \times 6 \times 8 \times 12\) | ||||||||||||
\(\ds \) | \(=\) | \(\ds 40 \times 6 \times 8 \times 12\) | ||||||||||||
\(\ds \) | \(=\) | \(\ds \paren {2^3 \times 5} \times \paren {2 \times 3} \times 2^3 \times \paren {2^2 \times 3}\) | ||||||||||||
\(\ds \) | \(=\) | \(\ds 2^9 \times 3^2 \times 5\) | ||||||||||||
\(\ds \) | \(=\) | \(\ds 23 \, 040\) |
$\blacksquare$