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## Perfect Numbers

__Definition :- __

A given number for which sum of all its factors is equal to it's twice, the number is known as **A Perfect Number**

Read the following examples to understand more about **Perfect Numbers**

**Examples 1 = **Is given number 6 a prime number ?
**Answer = ** Find the factors of given number 6

Factors of 6 = 1, 2, 3, 6.

Now, add all the above factors.

Sum = 1 + 2 + 3 + 6 = 12

Now, you can calculate that twice of given number 6 = 12

Since the sum of all the factors of 6 is equal to its twice

So, we can say that **6 is a perfect number.**

**Examples 2 = **Is given number 9 a prime number ?
**Answer = ** Find the factors of given number 9.

Factors of 9 = 1, 3, 9.

Now, add all the above factors.

Sum = 1 + 3 + 9 = 13

Now, you can calculate that twice of given number 9 = 18

Since the sum of the factors of 9 is not equal to its twice

Hence, we can say that **9 is not a perfect number.**

**Examples 3 = **Is given number 28 a prime number ?
**Answer = ** Find the factors of given number 28

Factors of 28 = 1, 2, 4, 7, 14, 28.

Now, add all the above factors.

Sum = 1 + 2 + 4 + 7 + 14 + 28 = 56

Now, you can calculate that twice of given number 28 = 56

Since, the sum of all the factors of 28 is equal to its twice

So, we can say that **28 is a perfect number.**