This is a simple Movable Type plugin to spell out numbers. 1 becomes one, 22 becomes twenty-two, etc. Lingua::EN::Numbers does the conversion; you will have to install it before number-spell.
Use the “number-spell” attribute in a tag to spell out numbers.
<$MTEntryCommentCount number_spell="1"$> comments
Only integers are properly handled.
Tested in MT 2.661 and 3.2.