is 23 odd or even?
Even numbers can be divided evenly into groups of two. The number four can be divided into two groups of two. Odd numbers can NOT be divided evenly into groups of two. ... 1, 3, 5, 7, 9, 11, 13, 15, 17, 19, 21, 23, 25, 27, 29, 31 are odd numbers.