9996

Number
$9996$ (nine thousand, nine hundred and ninety-six) is:


 * $2^2 \times 3 \times 7^7 \times 173$


 * The $4$th after $6999$, $7998$, $8997$ of the $4$-digit integers $m$ which need the largest number of reverse-and-add process iterations ($20$) before reaching a palindromic number:
 * $9996$, $16995$, $76956$, $\ldots$, $16668488486661$