What is a perfect number? Give example.

Explanation: A number for which the sum of all its factors is equal to twice the number is called a perfect number.

For example, the factors of 6 are 1,2,3 and 6.

So, 1+2+3+6 = 12 =12 * 6

Final Answer: A number for which the sum of all its factors is equal to twice the number is called a perfect number. For example,  is a perfect number.