1 and 40 share a certain feature, not exactly the same, but closely related. No other number exhibits this feature. What is it?

(In reply to Possible solution by Andre)

I will agree with your choice that ONE and FORTY are two numbers that are either lettered in reverse alphabetical or alphabetical sequence in English.  Let us not forget that the irrational number PI also has this characteristic (being spelled out in English with only 2 letters it would be very unlikely that such a number could not otherwise share the property), but I will assume that Ady was defining number as natural number. So, bravo!

Posted by Dej Mar on 2010-04-09 02:07:02