If you write out the numbers from 1 to 5000 in American English (e.g., THREE THOUSAND EIGHT HUNDRED SEVENTY-THREE), it turns out that only one of them has a unique number of characters.

Which is it?

Spaces and hyphens count as characters.

(In reply to computer solution by Charlie)

To be more specific,
THREE THOUSAND, has a unique length within the given range.
That length no longer is unique when the range is extended to 7000.

Posted by Dej Mar on 2016-03-12 01:58:00