Work out amicable numbers instantly with clear inputs, formula shown and shareable results.
Two numbers are amicable when each equals the sum of the other's proper divisors. The smallest pair is 220 and 284, known since antiquity. A number equal to its own aliquot sum is perfect rather than amicable.
Amicable pair
s(a) = b and s(b) = a with a ≠ b, where s is the sum of proper divisors
Yes, with 284. The proper divisors of 220 sum to 284 and those of 284 sum to 220.
1184 and 1210, found by Paganini in 1866 — remarkably overlooked by earlier mathematicians.