1. Prime Numbers
Any whole number greater than 1 that is divisible only by 1 and itself, is defined as a prime number. Consider an example of number 7, which has only two factors 1 and 7. This means it is a prime number. Let's take another example of the number 8, which has more than two factors, i.e 1, 2, 4, and 8. This means 8 is not a prime number.
1.1 List of Prime numbers
There are 25 prime numbers from 1 to 100. The complete list of prime numbers from 1 to 100 is given below:
List of Numbers | Prime Numbers |
Between 1 and 20 | 2, 3, 5, 7, 11, 13, 17, 19 |
Between 21 and 40 | 23, 29, 31, 37 |
Between 41 and 60 | 41, 43, 47, 53, 59 |
Between 61 and 80 | 61, 67, 71, 73, 79 |
Between 81 and 100 | 83, 89, 97 |
1.2 Properties of Prime Numbers
Some of the properties of prime numbers are as follows:
- A prime number is a whole number greater than 1.
- It has exactly two factors, that is, 1 and the number itself.
- There is only one even prime number, that is, 2.
- Every number can be expressed as the product of prime numbers.
2. Composite numbers
A composite number is divisible by the number itself, the number 1 and at least one other number. In other words, composite numbers are whole numbers that have more than two factors. Consider an example of number 16, which has more than two factors, i.e 1, 2, 4, 8 and 16. This means 16 is a composite number. Let's take another example of the number 11, which has only two factors 1 and 11. Hence, 11 is not a composite number.
3. Prime Numbers vs Composite numbers
Prime Numbers | Composite Numbers |
Prime Numbers are whole numbers greater than 1, having only two factors, 1 and the number itself. | Composite Numbers are the whole numbers greater than 1 having at least three factors. |
2 is the smallest and the only even prime number. | 4 is the smallest composite number. |
Examples of prime numbers are 2, 3, 5, 7, 11, etc. | Examples of composite numbers are 4, 6, 8, 9, 10, etc. |