What is a perfect number?

Answer 1

A perfect number is one whose positive integer factors, other than itself, add up to the number itself. For example, the factors of 6, other than itself, are 1, 2, 3, and 1 + 2 + 3 = 6. Therefore, 6 is a perfect number.

The first eight perfect numbers are:

• 6
• 28
• 496
• 8128
• 33550336
• 8589869056
• 137438691328
• 2305843008139952128

Answer 2

ten

* * * * *

No. 6 is the first followed by 28, 496 and then 8128.

A list is given at the link below: it only goes to the tenth perfect number but that is 54 digits long!