What are odd and even numbers?

Odd numbers are: 1, 3,5,7,9,1,13, 15, 17,19,2/kloc-. 57,59,6 1,63,65,67,69,7 1,73,75,77,79,8 1,83,85,87,89,9 1,93,95,97,99。

Even numbers are: 2, 4, 6, 8, 10, 12, 14, 16, 18, 20, 22, 24, 26, 28, 30.

Odd number: among integers, the number that is not divisible by 2 is odd, and the odd number can be represented by 2k+ 1, where k is an integer.

Even number: In an integer, the number divisible by 2 is even, and vice versa. Even number =2k and odd number =2k+ 1, where k is an integer.

Composite number: a positive integer divisible by other positive integers except 1 and itself. Even numbers except 2 are composite numbers. (except 0)

Prime number (also called prime number): All integers greater than 1 have no divisor except 1 and itself. This integer is called prime number or prime number. In other words, a prime number has only 1 and its own two divisors.