Introduction

A prime number is a number which is greater than 1(one). Prime number only has two factors i.e. 1(one) or its number itself. This means that these numbers will not be divided by any other number other than 1(one) and the number itself without leaving any remainder.

On the other hand, numbers that have more than 2(two) factors are called composite numbers.

Let us understand prime numbers in a more clear way with an example of a prime number between 1-100.

The image is given below-

A list of Prime Numbers between 1 and 100 is given below-

The prime number between 1 and 100 is 2,3, 5, 7, 11, 13, 17, 19, 23, 29, 31, 37, 41, 43, 47, 53, 59, 61, 67, 71, 73, 79, 83, 89 and 97. So, there are a total of 25(twenty-five) prime numbers between 1 and 100.

Terms Related to Prime Numbers

1. Co-Primes: Co-Prime number is defined as when any two numbers have only one common factor, that is, 1(one) and it is not necessary for co-prime numbers to be any prime numbers, for example, 5 and 7 are examples of co-primes.
2. Twin-Primes: A pair of prime numbers are called twin primes number when there is only one composite number between them, for example, (3, 5), (5, 7), (11, 13), (17, 19), etc.

Some Facts about Prime Numbers

1. 2(two) is the smallest prime number.
2. 2(two) is the only prime number that is even.
3. 2(two) and 3(three) are considered as consecutive prime numbers.
4. Except for 0(zero) and 1(one), any whole number is either a prime number or any composite number.
5. All the odd numbers are not always prime numbers, for example, 21, and 39 are odd numbers but not prime numbers.
6. No prime number greater than 5(five) ends in a 5(five).
7. For finding any prime numbers, the Sieve of Eratosthenes is one of the earliest methods.
8. When the number gets bigger the prime number becomes rarer.
9. In history, there is no largest prime number.

Main Content

• There are a total of 21(twenty-one) prime numbers in between the series of 100 and 200. The set of 100 to 200 contains only four fewer prime numbers in comparison to the other set of 1 to 100.

• The list of prime numbers between 100-200 is given below-

101, 103, 107, 109, 113, 127, 131, 137, 139,149,151,157, 163, 167, 173, 179, 181, 191, 193, 197 and 199.

• Therefore, there are a total of 21 prime numbers between 100 to 200. The numbers come only with two factors i.e. 1(one) and the number itself. Such numbers are called prime numbers.