Word that means the classification of a number as even or odd
Solution 1:
Parity
- Mathematics (of a number) the fact of being even or odd.
(Oxford Dictionaries)
Solution 2:
What about simply evenness? I think this would require less explanation than parity. If you mentioned parity to a non-mathematical readership, you'd definitely have to explain what was meant.
According to Wiktionary, evenness means:
The quality of being even.
https://en.wiktionary.org/wiki/evenness
and obviously one of those meanings of even is the one you're referring to.