Superabundant Number/Examples/12

From ProofWiki
Jump to navigation Jump to search

Example of Superabundant Number

The abundancy index of $12$ is:

$\dfrac {\map {\sigma_1} {12} } {12} = \dfrac {28} {12} = 2 \cdotp \dot 3$


Proof

\(\ds \map {\sigma_1} {12}\) \(=\) \(\ds 28\) $\sigma_1$ of $12$
\(\ds \leadsto \ \ \) \(\ds \dfrac {\map {\sigma_1} {12} } {12}\) \(=\) \(\ds \dfrac {28} {12}\)
\(\ds \) \(=\) \(\ds 2 \cdotp \dot 3\)

$\blacksquare$