Add them up.
2, 3, 4, 5, 6, 9, 10, 12, 15, 18, 20, 25, 30, 36, 45, 50, 60, 75, 90, 100, 150, 180, 225, 300, 450
154 is the sum of the proper factors of 256.
48
A perfect number is the term for a number that is equal to the sum of its proper divisors. Be careful not to confuse that with proper factors. Proper divisors include 1 but not the number itself. Proper factors don't include either I or the original number.
A perfect number.
2,340
Abundant is a number for which the sum of all its proper factors is greater than the number itself. Deficient is a number for which the sum of all its proper factors is less than the number itself. Perfect is a number for which the sum of all its proper factors is the number itself.
Zero. 5 is a prime so its only factors are 1 and 5. It, therefore, has no proper factors.
an abundant number is less than the sum of its proper divisors
The numbers for which the sum of its proper factors is 1 less than the number is the powers of 2; less than 50 these are: 2, 4, 8, 16 & 32.
2 + 5 + 10 + 25 = 42
53
53