3816

Number
$3816$ (three thousand, eight hundred and sixteen) is:


 * $2^3 \times 3^2 \times 53$


 * The $36$th octagonal number, after $1$, $8$, $21$, $40$, $65$, $\ldots$, $2296$, $2465$, $2640$, $2821$, $3008$, $3201$, $3400$, $3605$:
 * $3816 = \displaystyle \sum_{k \mathop = 1}^{36} \left({6 k - 5}\right) = 36 \left({3 \times 36 - 2}\right)$