No, but with a microflow you can build your own. It will take a lot of if statements though. After you finished this microflow you might want to publish this one so others can use it to. If you need pointers creating this microflow let us know, but it should be straight forward.
Regards,
Ronald
It's not a standard Mendix thingy you can use in your project AFAIK. However, I know I've seen this in one of my projects before, but can't seem to find it at the moment.
A custom Java action might help you though. Take a look here:
http://stackoverflow.com/questions/3911966/how-to-convert-number-to-words-in-java
Create a Java action to do this. A number of example implementations can be found at http://stackoverflow.com/questions/3911966/how-to-convert-number-to-words-in-java .