33,550,336

Number
$33 \, 550 \, 336$ is:


 * $2^{12} \times 8191$


 * The $5$th perfect number after $6$, $28$, $496$, $8128$:
 * $33 \, 550 \, 336 = \map {\sigma_1} {33 \, 550 \, 336} - 33 \, 550 \, 336 = 4096 \times 8191 = 2^{13 - 1} \paren {2^{13} - 1}$


 * The $4096$th hexagonal number:
 * $33 \, 550 \, 336 = \ds \sum_{k \mathop = 1}^{4096} \paren {4 k - 3} = 4096 \paren {2 \times 4096 - 1}$


 * The $8191$st triangular number:
 * $33 \, 550 \, 336 = \ds \sum_{k \mathop = 1}^{8191} k = \dfrac {8191 \times \paren {8191 + 1} } 2$