481

Number
$481$ (four hundred and eighty-one) is:


 * $13 \times 37$


 * The smallest positive integer whose square is the sum of $3$ fourth powers:
 * $481^2 = 12^4 + 15^4 + 20^4$


 * The $13$th octagonal number, after $1$, $8$, $21$, $40$, $65$, $96$, $133$, $176$, $225$, $280$, $341$, $408$:
 * $\ds 481 = \sum_{k \mathop = 1}^{13} \paren {6 k - 5} = 13 \paren {3 \times 13 - 2}$

Also see

 * Smallest Square which is Sum of 3 Fourth Powers