HN Explorer

Poll: Is Zero Even or Odd?

4 points by ColinWright ↗ HN
I've been in some interesting discussions recently, and as I drill down to find out what people think, this question arose.

As a number, is zero even or odd?

There's a twitter poll underway, so I thought I'd ask the same question here. So as a number, is zero even or odd? Speculation and discussion welcome in the comments.

5 comments

[ 3.1 ms ] story [ 26.8 ms ] thread
ColinWright
FWIW, the twitter poll is ... unsettling.
yorwba
0 : ℝ ↦ ℝ is both even and odd, because for all x ∈ ℝ, we have 0(x) = 0(-x) = -0(x).
ColinWright
That's why the wording here is specifically:

> As a number, is zero even or odd?

Treated as a number, not as a function.

isoblvck
By definition odd means the only factors are 1 and itself which clearly fails the definition of even is when divided by 2 there's 0 remainder which technically works but it also works for literally any number so it's neither even or odd
ColinWright
I think you are confusing or conflating the definitions of "odd" and "prime". I find I can't follow your reasoning at all, so let me give you my reasoning.

The accepted definition of "odd" is that when you divide by 2 you have a remainder of 1. Thus 7 is odd, because when you divide by 2 you get an answer of 3 with a remainder of 1. Similarly 15 is odd, because you divide by 2 to get an answer of 7 with a remainder of 1.

The accepted definition of "even" is that when you divide by 2 there is no remainder. Thus 18 is even because when you divide by 2 you get 9 and no remainder.

Rephrasing that, if you multiply any integer by 2, the result is always an even number. So 9 times 2 is 18, hence 18 is even. 23 times 2 is 46, hence 46 is an even number.

Then zero times 2 is zero, hence zero is an even number.