I'd try to keep it secret. I fear that if I came into such a sum I would have more "friends" than I ever wanted.
I doubt I would go on a shopping spree. Indeed, I think I would avoid buying much by way of real property at all. Part of the reason for "owning" real estate is for the long-term financial security it can help one attain. But if such security is no longer an issue, I'd just as soon have no property on which litigious sorts might trip and fall.
Yes Sir, when you have big bucks EVERYONE that sort of knows you will want to REALLY know you until you toss some moolah to them.