7998

Previous  ... Next

Number

$7998$ (seven thousand, nine hundred and ninety-eight) is:

$2 \times 3 \times 31 \times 43$

The $2$nd after $6999$ of the $4$-digit integers $m$ which need the largest number of reverse-and-add process iterations ($20$) before reaching a palindromic number:

$7998$, $16995$, $76956$, $\ldots$, $16668488486661$

Also see

• Previous  ... Next: 4-Digit Numbers forming Longest Reverse-and-Add Sequence

Sources

• 1986: David Wells: Curious and Interesting Numbers ... (previous) ... (next): $6999$
• 1997: David Wells: Curious and Interesting Numbers (2nd ed.) ... (previous) ... (next): $6999$