In a four-digit number, the product of the thousands digit and units digit is zero while their difference is 7. Product of the middle digits is 18. The thousands digit is as much more than the units…

The number is $7920$. The outer digits are $7$ and $0$ because the leading digit is nonzero, their product is zero, and their difference is $7$. The inner digits must multiply to $18$ and differ by $7$, so the hundreds digit is $9$ and the tens digit is $2$. The number $7290$ reverses their required order.