How many of the seven digits of 2389053 look exactly the same in their water images?

In these straight-stroke digits 0, 3 and 8 have a horizontal line of symmetry; 2, 5 and 9 turn into other shapes. The number contains 3, 8, 0 and 3: 4 digits. (2 counts the digits that survive an upright mirror, 0 and 8.)