8281

Number

$8281$ (eight thousand, two hundred and eighty-one) is:

$7^2 \times 13^2$

The $91$st square number after $1$, $4$, $9$, $16$, $25$, $36$, $\ldots$, $7396$, $7569$, $7744$, $7921$, $8100$:

$8281 = 91 \times 91$

The sum of the first $13$ cubes:

$8281 = 1^3 + 2^3 + 3^3 + 4^3 + 5^3 + 6^3 + 7^3 + 8^3 + 9^3 + 10^3 + 11^3 + 12^3 + 13^3$

The $1$st square number whose digits form $2$ consecutive integers, and the only one with $4$ digits:

$\mathbf {82} \, \mathbf {81} = 91^2$

The $1$st square number whose digits form $2$ consecutive decreasing integers:

$\mathbf {82} \, \mathbf {81} = 91^2$