418

Previous  ... Next

Number

$418$ (four hundred and eighteen) is:

$2 \times 11 \times 19$

The $7$th integer after $1$, $14$, $30$, $105$, $248$, $264$ whose divisor sum divided by its Euler $\phi$ value is a square:

$\dfrac {\map {\sigma_1} {418} } {\map \phi {418} } = \dfrac {720} {180} = 4 = 2^2$

The $47$th sphenic number after $30$, $42$, $66$, $70$, $\ldots$, $385$, $399$, $402$, $406$, $410$:

$418 = 2 \times 11 \times 19$

Arithmetic Functions on $418$

\(\ds \map {\sigma_0} { 418 }\)

\(=\)

\(\ds 8\)

$\sigma_0$ of $418$

\(\ds \map \phi { 418 }\)

\(=\)

\(\ds 180\)

$\phi$ of $418$

\(\ds \map {\sigma_1} { 418 }\)

\(=\)

\(\ds 720\)

$\sigma_1$ of $418$

Also see

• Previous  ... Next: Integers whose Ratio between Divisor Sum and Phi is Square
• Previous  ... Next: Sphenic Number