The Smallest Three

Number Theory Level pending

Find the sum of the smallest three numbers, such that the sum of their proper factors equals themselves.

Note: The problem was edited to "proper factors", which are (positive) factors which do not include the number itself.

2 solutions

Alex Segesta
May 10, 2014

Just look for the first 3 perfect numbers. 6+28+496=530

haha Alex, I borrowed this one from you

Asher Joy - 7 years, 1 month ago

Yeah, it's cool. XD

Alex Segesta - 7 years, 1 month ago

Ya but how to find perfect nos with just a pen nd a paper.Plz tl

Chandrachur Banerjee - 7 years ago

Perfect numbers = 2^(n-1) * [(2^n) - 1], where n are positive natural prime numbers.

Reeshabh Ranjan - 6 years, 11 months ago

Sunil Pradhan
Jul 3, 2014

Such numbers are called Perfect Numbers

for p = 2: 2^1(2^2−1) = 6

for p = 3: 2^2(2^3−1) = 28

for p = 5: 2^4(2^5−1) = 496

for p = 7: 2^6(2^7−1) = 8128