Does the UK Prime Minister Really Have Any Real Power?

I'm not really sure how much real genuine power the UK Prime Minister actually holds. Power is something that's mysterious. Power comes from a variety of things, and the UK PM doesn't really have much power. I've spoken in the past about the fact that there are various CEOs of various Fortune 500 companies in the US. Lots of these people are Indian origin people. And does that benefit India in any way whatsoever? It does not.