An integer divisible (without remainder) by $2$. Even numbers are: $0, \pm2, \pm4, \pm6, \pm8, \pm10,\dots$ An integer $k$ is even if and only if the last digit of $k$ is even. For example $2139856$ is even, while $2146903$ is not even (but odd).
An integer not divisible by 2 (i.e. leaving remainder 1) is called an odd number.
Even number. Encyclopedia of Mathematics. URL: http://www.encyclopediaofmath.org/index.php?title=Even_number&oldid=29130