In my design/idea gathering phase of a slowflying long range Solar powered motor-glider, I came upon he idea of having a 4 or even 6 bladed folding prop. If i understand it correctlly, the more blades, the slower the prop has to turn in order to produce the same amount of thrust. That's why some commuter turboprops, especially in europe, have 6 or even 7 bladed props. This reduces noise.It would only be solar powered - no batteries so it would be turning pretty slow by comparision. Are there any benifits to using these multi-bladed props, besides noise reduction?