6441

Number
$6441$ (six thousand, four hundred and forty-one) is:


 * $3 \times 19 \times 113$


 * The $57$th hexagonal number after $1$, $6$, $15$, $28$, $45$, $66$, $91$, $\ldots$, $4005$, $4186$, $4371$, $4560$, $4950$, $5151$, $5356$, $5565$, $5778$, $5995$, $6216$:
 * $6441 = \displaystyle \sum_{k \mathop = 1}^{57} \left({4 k - 3}\right) = 57 \left({2 \times 57 - 1}\right)$