8555

Number
$8555$ (eight thousand, five hundred and fifty-five) is:


 * $5 \times 29 \times 59$


 * The $29$th square pyramidal number after $1$, $5$, $14$, $30$, $55$, $\ldots$, $3311$, $3795$, $4324$, $4900$, $5525$, $6201$, $6930$, $7714$:
 * $8555 = \displaystyle \sum_{k \mathop = 1}^{29} k^2 = \dfrac {29 \left({29 + 1}\right) \left({2 \times 29 + 1}\right)} 6$