391

Number
$391$ (three hundred and ninety-one) is:


 * $17 \times 23$


 * The $17$th Smith number after $4$, $22$, $27$, $58$, $85$, $94$, $121$, $166$, $202$, $265$, $274$, $319$, $346$, $355$, $378$, $382$:
 * $3 + 9 + 1 = 1 + 7 + 2 + 3 = 13$