634

Number
$634$ (six hundred and thirty-four) is:
 * $2 \times 317$


 * The smallest positive integer which can be expressed as the sum of $2$ distinct lucky numbers in $25$ different ways


 * The $28$th Smith number after $4$, $22$, $27$, $58$, $\ldots$, $454$, $483$, $517$, $526$, $535$, $562$, $576$, $588$, $627$:
 * $6 + 3 + 4 = 2 + 3 + 1 + 7 = 13$