Another Puzzle for the Today Programme!

I set another puzzle for Radio 4's Today programme and it was featured this morning (Monday, 6th April 2020).

It goes like this...

"Doc note, I dissent. A fast never prevents a fatness. I diet on cod."

Bletchley Park Codebreaker Peter Hilton constructed this impressive 51-character palindromic sentence, allegedly in response to a challenge set by a fellow Codebreaker. Palindromic numbers work in the same way: the same digits in the same order whether you read them backwards or forwards.

What is the 51st Palindromic number?

You can find the puzzle (with a link to a solution) on the Today Programme's website, here.

As with many puzzles the solution is debatable depending on some starting assumptions. Feel free to discuss your assumptions (and how these might change the answer) in the comments. Teachers, I'd love to hear how you might use any of the ideas or topics featured (even tangentially) in your own teaching!

Also, please post your favourite palindromes!