8100

Number
$8100$ (eight thousand, one hundred) is:


 * $2^2 \times 3^4 \times 5^2$


 * The $34$th square number after $1$, $4$, $36$, $121$, $144$, $256$, $\ldots$, $5184$, $5776$, $6084$, $6400$, $7056$, $7744$ to be the divisor sum value of some (strictly) positive integer:
 * $8100 = \map {\sigma_1} {3560}$


 * The $90$th square number after $1$, $4$, $9$, $16$, $25$, $36$, $\ldots$, $6084$, $6241$, $6400$, $6561$, $6724$, $6889$, $7056$, $7225$, $7396$, $7569$, $7744$, $7921$
 * $8100 = 90 \times 90$