I probably had a gifted kid but never had enough bandwidth to lead him, comparing to his siblings he just memorizes so well(e.g, mechanically memorized PI to 60

I probably had a gifted kid but never had enough bandwidth to lead him, comparing to his siblings he just memorizes so well(e.g, mechanically memorized PI to 600+ digits in two days until I asked him to stop), doing high-school-level math at 4th grade, learn many things by himself and so on. Meanwhile he is bored, hard to make peer friends due to lack of shared interests, etc. Everyday I have to work and care for other kids, I tried to home-school him but then you get the financial pressure quickly. I wish there are some programs that can help kids like him, i.e. group them somewhere to study and learn from each other. We have quite some program taking care of the disadvantaged kids, what about the gifted ones? After all, they can potentially contribute to the society in some way that helps many others. We probably need a state-level or federal-level or even college-sponsored program for those really gifted kids. No I'm not talking about the gifted class in the school district, those helps, but far from enough for those really gifted, you probably only have about 5 who are really gifted in each school district.