Problem 44748. Amicable numbers

Created by cdeliu

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Test whether two numbers are amicable, meaning that the sum of the proper divisors of each number is equal to the other number.

Example: 220 and 284 are amicable numbers because the proper divisors of 220 are 1,2,4,5,10,11,20,22,44,55,110 and their sum is 284, while the proper divisors of 284 are 1,2,4,71,142 and their sum is 220.

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Solution Stats

34 Solutions
11 Solvers

Last Solution submitted on Jan 08, 2020

Last 200 Solutions

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Kristopher Powers on 23 Oct 2018

use of divisors is not allowed.

cdeliu on 24 Oct 2018

I think it's because divisors is part of a toolbox, I did not set it up not to allow it.

Kristopher Powers on 24 Oct 2018

@cdeliu I have solved another problem in Community and I still am unable to see the best solution. Could you help to give advice on this.

cdeliu on 24 Oct 2018

If divisors function is not allowed, you should somehow generate these divisors. The best solution uses the mod function.

Solution Comments

Solution 1659624

1 Comment

1 Comment

Kristopher Powers on 25 Oct 2018

I performed speed analyses on this and Solution 1659562 is faster by leaps and bounds if you can see this solution your doing good. I performed this as a hack as I was unable to see the real solutions even after solving others in the community.

Solution 1657032

1 Comment

1 Comment

Kristopher Powers on 25 Oct 2018

Very impressive.

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divisors number theory

Problem 44748. Amicable numbers

Solution Stats

Last 200 Solutions

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Problem Recent Solvers11

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Problem 44748. Amicable numbers

Solution Stats

Last 200 Solutions

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Solution Comments

Problem Recent Solvers11

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