Maximum common factor = 10 30 = 2 30 * 5 30

Number of common factors = (30+1) * (30+1) = 961.

That is, the number from 1, 2,5, 10 ... to 10 30, * * 96 1 is the common factor of1040,2030.

Because according to combinatorial mathematics, it is equivalent to all the methods of taking out 0, 1 2 ... 60 balls come from 30 red balls and 30 white balls.