I could do it, but would be buying a lot of stuff I don't really want/need.
Also, it really depends on the definition of investment. Could buy a lot of cool property that I'd have to overpay for and lose money. Which might make it less of an investment.
If I had to spend and couldn't donate or invest, I'd get/build multiple houses in cool locations (Tahoe/Newport/ Park City/ Condo in NY/ Hawaii). Buy a crazy yacht. Get a Gulfstream and customize a 787 in case I ever wanted to take more people somewhere.
I'd have helipads at each house and on the yacht and helicopters at each airport nearest each property.
Maybe build a private golf course or two. Buy, some cool old military ships/tanks. And, get tons of cool sport memoribilia and other artifacts.
Since buying a sports team isn't an option but I'd get boxes and front row tickets to any sporting event.
Maybe buy some Superbowl ads promoting things I care about or maybe just try to make a funny ad. ( Maybe this counts as philanthropy)
I bet I could do it. But, probably wouldn't really want all that stuff.