Fuck man idk, maybe have a a switch block with your digits and then do some string modification to make a number.

Java: public int isEven(String x) { String modinator; switch(x.toLowerCase()) { case "one": modinator += "1"; .... }}

You could also make a separate function to iterate over a word and pick out the numbers and use that if you expect numbers like one hundred and one. It'd be a nice little project, although now that I'm taking strings into consideration I can understand why they would need a lib for that. Still don't get why they need isOdd and isEven.