9855

Number
$9855$ (nine thousand, eight hundred and fifty-five) is:


 * $3^3 \times 5 \times 73$


 * The magic constant of the order $27$ magic square:
 * $9855 = \dfrac {27 \left({27^2 + 1}\right)} 2$


 * The magic constant of a magic square of order $27$, after $1$, $(5)$, $15$, $34$, $\ldots$, $2465$, $2925$, $3439$, $4010$, $4641$, $5335$, $6095$, $6924$, $7825$, $8801$:
 * $9855 = \displaystyle \dfrac 1 {27} \sum_{k \mathop = 1}^{27^2} k = \dfrac {27 \paren {27^2 + 1} } 2$