Composite Numbers Definition
In Mathematics, you must have learned about different sets of numbers including Natural numbers, Whole numbers, and Integers. A specific type of number is called a Composite number that we are going to discuss here on this page.
Note:
You can read about Prime numbers, Rational numbers and Square numbers here.
All numbers that are made by multiplying two or more whole numbers are called “Composite Numbers”. In simple words, a number that has at least two factors is called a composite number.
24 is a composite number because it has “4” factors i.e. 2 x 2 x 2 x 3.
So, we can say that a number that is formed by multiplying different prime numbers is called a composite number.
What is the difference between Prime & Composite Numbers?
To understand composite numbers deeply, you need to know a little about prime numbers. Those numbers that are not divisible by any other number are called Prime numbers. For example, 3 is a prime number because it is not divisible by any number except 3.
Note:
Read about Prime Numbers here.
Composite and Prime numbers are opposite to each other in all aspects. A composite number can be formed by multiplying different prime numbers but a prime number can’t be made from composite numbers.
Types of Composite Numbers
There are two main types of composite numbers in Mathematics.
Odd Composite Numbers:
All those composite numbers that have an odd number at their unit places.
For example,
9, 15, 21, and 27 are odd composite numbers.
Note:
Read about Odd Numbers here.
All those numbers that have even numbers at their unit places.
For example,
12, 26, and 36 are even composite numbers.
Note:
Read about Even Numbers here.
Fun Facts about Composite Numbers
- A composite number has at least 2
- All even numbers are composite except 2.
- Prime numbers can make a composite number while a composite number can’t make a prime number.
- A composite number can be divided by other composite numbers.
How to check if a number is composite or not?
To check whether a number is composite or prime, you should follow a few steps.
- Divide the given number by prime numbers
- If the number has more than two factors except 1 as it’s divisible, then it will be termed as a composite number.
In simple words, you have to do Prime Factorization of the given number to find all of its factors.
Note:
You can learn about Prime Factorization here in detail.
List of Composite Numbers from 1 to 100
FAQ's
What is the smallest Composite Number?
“4” is the smallest composite number.
Can a number be prime and composite at the same time?
No, a number can’t be a prime number and a composite number at the same time.
Is 0 a composite number?
No, 0 is neither a composite number nor a prime number. It is termed as a whole number only.
Why 1 is not a composite number?
1 is not a composite number because it has only one factor which is “1” itself.
What is the smallest odd composite number?
The smallest odd composite number is “9”
How to find factors of a composite number?
Through prime factorization, we can find factors of a composite number.
Are all even numbers composite numbers?
All even numbers are composite numbers except “2”.
