9126

Number
$9126$ (nine thousand, one hundred and twenty-six) is:


 * $2 \times 3^3 \times 13^2$


 * The $26$th pentagonal pyramidal number after $1, 6, 12, 40, 75, \ldots, 1470, 1800, 2176, 2601, 3078, 3610, 4200, 4851, 5566, 6348, 7200, 8125$:
 * $9126 = \displaystyle \sum_{k \mathop = 1}^{26} \dfrac {k \left({3 k - 1}\right)} 2 = \dfrac {26^2 \left({26 + 1}\right)} 2$