Such as 220 and 284:
The total divisor of 220 (excluding itself) is:1+2+4+5+11+20+22+44+55+1.
The sum of all divisors of 284 (excluding 284 itself) is:1+2+4+71+142 = 220.
In other words, the affinity number can be said to be two positive integers, and the sum of all the divisors on one side is equal to the sum of all the divisors on the other side.
The sum of all divisors of 220 is:1+2+4+5+10+/kloc-0+20+22+44+55+10+220.
The sum of all divisors of 284 is1+2+4+71+142+284 = 220+284 = 504.
The directory [hidden [edited] has a history of about 320 years. 220 and 284, discovered by Pythagoras in ancient Greece, are the first known blind date.
About 850 years ago, Tabbert Ben Cora, an Arab mathematician, discovered the formula of blind date number, which was later called Tabbert Ben Cora's law.
1636, Fermat found another pair of blind dates: 17296 and 184 16.
1638, Descartes also found a pair of blind date objects: 9363584 and 9437056.
Euler also studied the topic of the number of blind dates. 1750, he threw 60 pairs of blind date objects to the public in one breath: 2620 and 2924, 5020 and 5564, 6232 and 6368, …, which caused a sensation.
1866, 16-year-old Italian youth Bargeny found that 1 184 and 12 10 were the second blind date, only slightly older than 220 and 284.
At present, people have found 1200 pairs of blind date objects. However, whether there are infinite pairs of blind date objects, whether the two numbers of blind date objects are both odd or even, whether there are odd or even numbers and so on. These problems remain to be discussed.