756

Number
$504$ (seven hundred and fifty-six) is:


 * $2^2 \times 3^3 \times 7$


 * The $2$nd positive integer after $504$ which can be expressed as the product of $2$ two-digit numbers in $2$ ways such that the factors in one of those pairs is the reversal of each of the factors in the other:
 * $756 = 12 \times 63 = 36 \times 21$