636

Number
$636$ (six hundred and thirty-six) is:
 * $2^2 \times 3 \times 53$


 * The $29$th Smith number after $4$, $22$, $27$, $58$, $\ldots$, $454$, $483$, $517$, $526$, $535$, $562$, $576$, $588$, $627$, $634$:
 * $6 + 3 + 6 = 2 + 2 + 3 + 5 + 3 = 15$