742

Number
$742$ (seven hundred and forty-two) is:


 * $2 \times 7 \times 53$


 * The $8$th Keith number after $14$, $19$, $28$, $47$, $61$, $75$, $197$:
 * $7$, $4$, $2$, $13$, $19$, $34$, $66$, $119$, $219$, $404$, $742$, $\ldots$


 * The $34$th number whose divisor sum is square:
 * $\map {\sigma_1} {742} = 1296 = 36^2$