The two integers are A and A+40 or, equivalently, B and B-40.
The sum of the first 40 positive integers (1-40) is: 820
The sum of the first 40 even positive integers can be equal to 820.
It is 40*41/2 = 820
The only factor they have in common is 1, but they are both positive integers between 20 and 40.
41 is between the integers 40 and 42.
90
75 = 40 + 35
10 20 30 40 50...
8
Using only positive integers:1x1202x63x404x305x226x208x1510x12
9 of them.
The difference between 43 and 40 is 3.