341

Number
$341$ (three hundred and forty-one) is:


 * $11 \times 31$


 * The $11$th octagonal number, after $1, 8, 21, 40, 65, 96, 133, 176, 225, 280$:
 * $341 = 1 + 7 + 13 + 19 + 25 + 31 + 37 + 43 + 49 + 55 = \displaystyle \sum_{k \mathop = 1}^n \left({6 k - 7}\right) = 11 \left({3 \times 11 - 2}\right)$


 * The $1$st Poulet number:
 * $2^{341} \equiv 2 \pmod {341}$: $341 = 11 \times 31$