even+or+odd

20 is a even number because 20 is divisible by 2 and 2x10=20 and when a number is divisible by 2 that means there is nothing left over and it is what you call a even number.
== 20 is not a odd number because odd numbers always have some left overs or remainders because odd numbers never end in a 0,or 2 so then you can try to see if it will work out but it wont because there will be a left overs.some odd numbers are 3,7,11,19,28,29 ==