Arithmetic Course/Types of Number/Natural Number

Natural Number
Natural Number is a set of all digits from 0 to 9
 * N = {1,2,3,4,5,6,7,8,9}

Even Number
Natural Number divisible by two is called Even Number
 * 2N = {2,4,6,8}

Odd Number
Natural Number not divisible by two is called Odd Number
 * 2N + 1 = {1,3,5,7,9}

Prime Number
prime number"p"" is the number that have 4 divisors [p,-p,1,-1]
 * p=[2,3,5,7,9,11,.................]