6426

Number
$6426$ (six thousand, four hundred and twenty-six) is:


 * $2 \times 3^3 \times 7 \times 17$


 * The $51$st heptagonal number after $1$, $7$, $18$, $34$, $5$, $81$, $112$, $\ldots$, $3744$, $3940$, $4141$, $4347$, $4558$, $4774$, $4995$, $5221$, $5452$, $5688$, $5929$, $6175$:
 * $6426 = \displaystyle \sum_{k \mathop = 1}^{51} \left({5 k - 4}\right) = \dfrac {51 \left({5 \times 51 - 3}\right)} 2$