What decides if a helicopter gets 2/4/6 blades?

Question

As the title says, why do Hueys have 2 blades, while most others have 4, or the Sea Stallion has 6? And if you put 6 on a 4, does that mean more lift and better performance?

In: 490

Answer 1

For the Sea Stallion, the 53D and older, is 2 engine and 6 blades

The CH and MH-53Es have 3 engines and 7 blades