5208

Number
$5208$ (five thousand, two hundred and eight) is:


 * $2^3 \times 3 \times 7 \times 31$


 * The $42$nd octagonal number, after $1$, $8$, $21$, $40$, $65$, $\ldots$, $3008$, $3201$, $3400$, $3605$, $3816$, $4033$, $4256$, $4485$, $4720$, $4961$:
 * $5208 = \displaystyle \sum_{k \mathop = 1}^{42} \left({6 k - 5}\right) = 42 \left({3 \times 42 - 2}\right)$