If you look at spending $1,000,000 alone it is difficult, without wasting it. Unless you donate a lot or buy twenty-four houses. By difficult I mean spending it realistically. Thats a lot o' moola.
I would probably build a museum somewhere with the worlds greatest technology for an astronomical observatory, a giant library, and a world class educational facility, where the worlds greatest minds could meet and the public could learn and have fun for free.