Numbers such that Divisor Count divides Phi divides Divisor Sum/Examples/248

Examples of Numbers such that Divisor Count divides Phi divides Divisor Sum

The number $248$ has the property that:

$\map {\sigma_0} {248} \divides \map \phi {248} \divides \map {\sigma_1} {248}$

where:

$\divides$ denotes divisibility

$\sigma_0$ denotes the divisor count function

$\phi$ denotes the Euler $\phi$ (phi) function

$\sigma_1$ denotes the divisor sum function.

Proof

\(\ds \map {\sigma_0} {248}\)

\(=\)

\(\, \ds 8 \, \)

\(\ds \)

$\sigma_0$ of $248$

\(\ds \map \phi {248}\)

\(=\)

\(\, \ds 120 \, \)

\(\, \ds = \, \)

\(\ds 15 \times 8\)

$\phi$ of $248$

\(\ds \map {\sigma_1} {248}\)

\(=\)

\(\, \ds 480 \, \)

\(\, \ds = \, \)

\(\ds 4 \times 120\)

$\sigma_1$ of $248$

$\blacksquare$