True, Zero is even number but its neither positive nor negative. But I do have a doubt as zero comes under natural numbers, those are non-negative integers. So, I think we can treat this as positive.
Natural numbers starts from 1 not 0
whole numbers starts from 0
Natural numbers are subset of whole number.
Whole numbers := [0,natural numbers]
I was also thinking the same but wikipedia changed my decision, check out this link.
may be wiki is wrong on this..