6216

Number
$6216$ (six thousand, two hundred and sixteen) is:


 * $2^3 \times 3 \times 7 \times 37$


 * The $56$th hexagonal number after $1$, $6$, $15$, $28$, $45$, $66$, $91$, $\ldots$, $4005$, $4186$, $4371$, $4560$, $4950$, $5151$, $5356$, $5565$, $5778$, $5995$:
 * $6216 = \displaystyle \sum_{k \mathop = 1}^{56} \paren {4 k - 3} = 56 \paren {2 \times 56 - 1}$


 * The $111$th triangular number after $1$, $3$, $6$, $10$, $15$, $\ldots$, $5253$, $5356$, $5460$, $5565$, $5671$, $5778$, $5886$, $5995$, $6105$:
 * $6216 = \displaystyle \sum_{k \mathop = 1}^{111} k = \dfrac {111 \times \paren {111 + 1} } 2$