Prime and Composite Numbers.

PRIME AND COMPOSITE NUMBERS:   

Factors are either composite numbers or prime numbers.

PRIME NUMBER:

A prime number has only two factors, one:’1’ and number itself.

It cannot be divided evenly by any other numbers. Here's a list of prime numbers up to 100. These Prime numbers cannot be factored any further.

PRIME NUMBERS up to 100

2, 3, 5, 7, 11, 13, 17, 19, 23, 29, 31, 37, 41, 43,
47, 53, 59, 61, 67, 71, 73, 79, 83, 89, 97.

COMPOSITE NUMBER:

A composite number is any number that has more than two factors.

Here is a list of composite numbers up to 20.The composite numbers can be factored further.

For example: 4 = 2* 2 ; 6= 3 * 2 ; 8 = 4 * 2; and so forth.

COMPOSITE NUMBERS up to 20

4, 6, 8, 9, 10, 12, 14, 15, 16, 18, 20.

UNIQUE NUMBER:

The number ‘1’, is neither prime nor composite number. It is called a Unique number. Unique number has only one factor.

CONSECUTIVE PRIME NUMBERS:

The prime numbers which come one after the other are called Consecutive Prime Numbers.

PRIME NUMBERS up to 100 :  2, 3, 5, 7, 11, 13, 17, 19, 23, 29, 31, 37, 41, 43,
47, 53, 59, 61, 67, 71, 73, 79, 83, 89, 97.

From the above list of Prime numbers up to 100: Only 2 and 3 comes one after other. So, they are Consecutive Prime Numbers.  

TWIN PRIMES:

Two Prime numbers which have a composite number in between are called Twin Primes.

The two Prime numbers 3 and 5, which have composite number,4  in between. Thus Prime numbers 3 and 5 are called Twin Primes.

The pair of Twin primes are: 3 and 5 ; 5 and 7; 11 and 13; 17 and 19;29 and 30; 41 and 43; 59 and 60;  71 and 73 .