Prime numbers

Numbers are classified into two categories, prime numbers and composite number. Let us learn about prime numbers. What is a prime number? Or what is prime number? Prime number is a positive whole number which can only be divisible by 1 and itself. For example: - 2, 3, 5, 7 etc.

Prime number only has two factors.  A list of prime number up to 100 is given as follows:-
• 2 = 1 X 2
• 3 = 1 X 3
• 5 = 1 X 5
• 7 = 1 X 7
• 11 = 1 x 11
• 13 = 1 X 13
• 17 = 1 X 17
• 19 = 1 X 19
• 23 = 1 X 23
• 29 = 1 X 29
• 31 = 1 X 31
• 37 = 1 X 37
• 41 = 1 X 41
• 43 = 1 X 43
• 47 = 1 X 47
• 53 = 1 X 53
• 59 = 1 X 59
• 61 = 1 X 61
• 67 = 1 X 67
• 71 = 1 X 71
• 73 = 1 X 73
• 79 = 1 X 79
• 83 = 1 X 83
• 89 = 1 X 89
• 97 = 1 X 97
All these numbers listed above makes a list of prime numbers upto 100. We can list prime numbers in such a way. All these numbers are divisible by number one and themselves. Rest all other numbers are known as composite numbers. Following is the prime numbers chart of numbers up to 100:-

Prime number

 So this makes a prime number chart. All those numbers marked in blue are prime numbers. Now the question arises, is 1 a prime number? 1 is not a prime number, by definition a prime number is a number that is divided by one and itself so 1 does not fit under the definition of a prime number. Hence, 1 is not a prime number. It is the building block of the positive integers. A prime number should have two factors but number just has one factor that is 1, therefore it is not considered as a prime number.