Factors and Perfect Numbers
Factors of a number N are numbers that are less
than or equal to the number N which, when some of them are multiplied
together, give the number N.
Example: The factors of 6 are 1,2,3 and 6. When 2 and 3 are multiplied
together, they give 6 and so do 1 and 6 when multiplied together.
A Perfect Number is a number N whose factors that
are less than itself add to the same number N.
Example: The factors of 6 are 1,2,3,6. The factors that are less
than 6 are 1,2 and 3. Adding 1 + 2 + 3 = 6. This makes 6 a perfect number.
Very few perfect numbers exist, as can be verified here.