A certain number ends with the digit 2. Moving the 2 from the end of the number to its front doubles it. Can you find this number?

(Hint: it's quite large)

I actually wrote a program to go through and find this number... since it was so huge, I spent the majority of my time optimising the code. Also, I ran into some precision problems since the answer of the order of magnitude of 1e+17. Cool problem.

Posted by Tom on 2002-05-09 12:15:01