Zero is an even number. In other words, its parity—the quality of an integer being even or odd—is even. Coincidentally an even parity is denoted parity 0. Therefore it is true that 0 has parity 0.
Zero fits the definition of an even number: An even number is an integer of the form n = 2k where k is an integer. It also exhibits all properties shared by all even numbers, including but not limited to:
- being divisible by 2
- being surrounded on both sides by odd integers
- able to be split into two equal groups
Zero also fits the rules for sums and products of even numbers, such as even − even = even, so any alternate definition of "even number" would still need to include zero.