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 $1$, $7$, $18$, $34$, $55$, $81$, $112$, $\ldots$, $3744$, $3940$, $4141$, $4347$, $4558$, $4774$, $4995$, $5221$, $5452$, $5688$, $5929$, $6175$:
 * $6426 = \ds \sum_{k \mathop = 1}^{51} \paren {5 k - 4} = \dfrac {51 \paren {5 \times 51 - 3} } 2$