369

Number
$369$ (three hundred and sixty-nine) is:


 * $3^2 \times 41$


 * The number of distinct octominoes, up to reflection.


 * The magic constant of the order $9$ magic square:
 * $369 = \dfrac {9 \paren {9^2 + 1} } 2$

Also see

 * 369 Octominoes