490

Number
$490$ (four hundred and ninety) is:


 * $2 \times 5 \times 7^2$


 * The $11$th primitive semiperfect number after $6$, $20$, $28$, $88$, $104$, $272$, $304$, $350$, $368$, $464$:
 * $490 = 2 + 5 + 7 + 14 + 49 + 70 + 98 + 245$


 * The smallest positive integer which can be expressed as the sum of $2$ distinct lucky numbers in $23$ different ways


 * The $48$th noncototient after $10$, $26$, $34$, $50$, $\ldots$, $386$, $394$, $404$, $412$, $436$, $466$, $470$, $474$, $482$:
 * $\nexists m \in \Z_{>0}: m - \map \phi m = 490$
 * where $\map \phi m$ denotes the Euler $\phi$ function