520

Number
$520$ (five hundred and twenty) is:
 * $2^3 \times 5 \times 13$


 * The $50$th noncototient after $10, 26, 34, 50, \ldots, 470, 474, 482, 490, 518$:
 * $\nexists m \in \Z_{>0}: m - \phi \left({m}\right) = 520$
 * where $\phi \left({m}\right)$ denotes the Euler $\phi$ function

Also see

 * This sequence will not be tabulated further on .
 * This sequence will not be tabulated further on .