7825

Number
$7825$ (seven thousand, eight hundred and twenty-five) is:


 * $5^2 \times 313$


 * The magic constant of a magic square of order $25$, after $1$, $(5)$, $15$, $34$, $\ldots$, $2465$, $2925$, $3439$, $4010$, $4641$, $5335$, $6095$, $6924$:
 * $\ds 7825 = \dfrac 1 {25} \sum_{k \mathop = 1}^{25^2} k = \dfrac {25 \paren {25^2 + 1} } 2$