Question

A perfect number is a number whose sum of factors is equal to

• A. thrice the number.
• B. the number itself.
• C. twice the number.

Answer 1

The correct option is C twice the number.

A perfect number is a number whose sum of factors is equal to twice the number.

For example, 6 is a perfect number since the sum of its factors i.e. 1, 2, 3 and 6 is 12 i.e. twice of 6.

A perfect number is also defined as a positive integer that is equal to the sum of its positive divisors including 1 but excluding the number itself.

Taking the same example of number 6: Its factors other than 6 are: 1, 2, 3 and 1+2 +3 = 6.