4950

Number
$4950$ (four thousand, nine hundred and fifty) is:


 * $2 \times 3^2 \times 5^2 \times 11$


 * The $12$th Kaprekar number after $1, 9, 45, 55, 99, 297, 703, 999, 2223, 2728, 4879$:
 * $4950^2 = 24 \, 502 \, 500 \to 2450 + 2500 = 4950$