Divisor Sum of 9135
Jump to navigation
Jump to search
Example of Divisor Sum of Integer
- $\map {\sigma_1} {9135} = 18 \, 720$
where $\sigma_1$ denotes the divisor sum function.
Proof
We have that:
- $9135 = 3^2 \times 5 \times 7 \times 29$
Hence:
\(\ds \map {\sigma_1} {9135}\) | \(=\) | \(\ds \dfrac {3^3 - 1} {3 - 1} \times \paren {5 + 1} \times \paren {7 + 1} \times \paren {29 + 1}\) | Divisor Sum of Integer | |||||||||||
\(\ds \) | \(=\) | \(\ds \dfrac {26} 2 \times 6 \times 8 \times 30\) | ||||||||||||
\(\ds \) | \(=\) | \(\ds 13 \times 6 \times 8 \times 30\) | ||||||||||||
\(\ds \) | \(=\) | \(\ds 13 \times \paren {2 \times 3} \times 2^3 \times \paren {2 \times 3 \times 5}\) | ||||||||||||
\(\ds \) | \(=\) | \(\ds 2^5 \times 3^2 \times 5 \times 13\) | ||||||||||||
\(\ds \) | \(=\) | \(\ds 18 \, 720\) |
$\blacksquare$