Indeed. And Euclid’s definition of evenness (Def VII.6) applies only to numbers, which for Euclid excludes both 0 and 1. So there’s at least one vaguely axiomat

Indeed. And Euclid’s definition of evenness (Def VII.6) applies only to numbers, which for Euclid excludes both 0 and 1. So there’s at least one vaguely axiomatic formulation of number theory where the correct answer is probably “neither because it’s not the sort of object to which you can predicate evenness or oddness”.