667

Number
$667$ (six hundred and sixty-seven) is:


 * $23 \times 29$


 * The $7$th tri-automorphic number after $2$, $5$, $7$, $67$, $75$, $92$:
 * $667^2 \times 3 = 1 \, 334 \, \mathbf {667}$