How To Find out the Factors of 21 –
We have to find the factors of number 21. Factors are the numbers which when divided by number 21 we get the factors.
When we make pair of factors the multiplication of pair of factors gives the given number.
Steps to find Factors of 21:
1) Firstly we divide given number 21 to get remainder 0.
2) After getting answers all numbers we get are called Factors of given number.
3) 1 is the only number having factor of all numbers.
4) The given number itself is the highest factor of given number.
We find factors of 21:
Here,
We get factors of 21 are 1, 3, 7 and 21.
We know,
A number which has more than two factors is called composite number.
A number 21 has more than two factors.
Hence, 21 is composite number.
Also
We know,
A number which is not divided by any other number is called prime number.
In factors of 21 we get 3and 7 are the prime number.
Now we find prime factorization of 21 by using LCM.
Prime factors of 21 = 3 x 7
Prime factors of 21 = 3 x 7
There are 4 factors of 21 i.e. 1, 3, 7 and 21.
When we make pairs of factors the multiplication of that two factors is the given number itself.
Pairs of factors of 21: 1 x 21, 3 x 7.
Pairs of factors of 21: (1, 21) and (3, 7)
We know Multiplication Property,
a x b = b x a
I.e. Pairs of factors of 21: (21, 1) and (7, 3) is also same.
- All factors of 21 = 1, 3, 7, 21.
- Prime factor of 21 = 3 x 7
- Sum of all factors of 21 = 1 + 3 + 7 + 21 = 32
- Pairs of factors of 21: (1, 21) and (3,7) also (21, 1) and (7, 3)