How many rotation of planet gear done in one rotation of sun gear?

This one of the design choices to be made by the gear designer. Usually, a simple ratio may be first decided upon, but then a gear ratio is chosen such that the lowest common multiple of the gears will be a large number.

This is so that a burr or damage on one gear tooth will be smoothed during in the next many revolutions, before the burr will repeat its position. Otherwise, the damage would result in an easily detected vibration.

Thus instead of (say) a ratio of 4:1, the designer could choose 41:11.