A has nine different divisors, so A is a square number, and the minimum value is 2? ×3? =36

B has six different divisors, and the smallest is 2? ×3= 12,

Ab is not divisible by each other, so the smallest B can only be 2? ×5=20

C has eight different divisors, and the smallest is 2×3×5=30.

The minimum product of three numbers is: 36×20×30=2 1600.