2728

Number
$2728$ (two thousand, seven hundred and twenty-eight) is:


 * $2^3 \times 11 \times 31$


 * The $10$th Kaprekar number after $1$, $9$, $45$, $55$, $99$, $297$, $703$, $999$, $2223$:
 * $2728^2 = 7 \, 441 \, 984 \to 744 + 1984 = 2728$