what is the main reason for it being an even number?
Zero is an integer multiple of 2, namely so zero is even.
Parity of zero
A number is called "even" if it is an integer multiple of 2. As an example, the reason that 10 is even is that it equals . In the same way, zero is an integer multiple of 2, namely so zero is even.

what is the parity of zero? The quality of an integer being even or odd—is even. who invented the number zero? Indian mathematician Brahmagupta is this number an even or odd number? Even number
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Parity of zero [SEP] Why zero is even
The standard definition of "even number" can be used to directly prove that zero is even. A number is called "even" if it is an integer multiple of 2. As an example, the reason that 10 is even is that it equals . In the same way, zero is an integer multiple of 2, namely so zero is even. It is also possible to explain why zero is even without referring to formal definitions. The following explanations make sense of the idea that zero is even in terms of fundamental number concepts. From this foundation, one can provide a rationale for the definition itself—and its applicability to zero.