Answer :
The smallest pair of amicable numbers is (220, 284). They are amicable because the proper divisors of 220 are 1, 2, 4, 5, 10, 11, 20, 22, 44, 55 and 110, of which the sum is 284; and the proper divisors of 284 are 1, 2, 4, 71 and 142, of which the sum is 220.
Amicable numbers are a pair of numbers such that the sum of their
proper divisors (not including itself) equals the other number.
Because amicable numbers must come in pairs, they are sometimes called
amicable pairs or amicable partners.
For example, show that 220 and 284 are amicable numbers:
First, find the proper divisors of 220:
1, 2, 4, 5, 10, 11, 20, 22, 44, 55, 110
If you add all these numbers together, you can see they sum to 284.
Now find the proper divisors of 284:
1, 2, 4, 71, 142
These sum to 220.
Thus, 220 and 284 are a pair of amicable numbers.