investment opportunities are endless really. I’d buy real estate & develop it for resale - relatively easy profits there. US FDIC only insures up to 250k per account, but there are other country’s banks out there - the Swiss banking system was a popular choice in the past but I’ve heard that the Cayman Island banking system is good as well. invest in tech - small businesses, as a few tens of millions isnt going to go that far, but 100 mil is good seed capital.
or, shit, just retire on it & pass the remains to your descendants.