There are an infinite number of them.
If you're only interested in positive, whole numbers, then there are 8 of them:
1, 2, 4, 5, 8, 10, 20, and 40.
Eleven.
40, 80, 120, 160, 200 +40 . . .
It is 1
Not as a whole number because 1/40 = 0.025
2..
The gcf is 8
40/8=5
40 and 63 have no common prime factors.
2000 ÷ 40 = 50
40 times.
40
40 of them.