I wouldn't tell a soul. Like@MiNi Beast, I'd sit on it for a while.
I'd seek out that law firm that represented the last big winner, so as to collect anonymously, and take the cash option (which, by the way is
about half BEFORE taxes). Then I'd let the dust settle, the world knowing it's been claimed.
Meanwhile I'd set a up a trust with a group of named benefactors (family and true friends) who would receive "enough" to meet unexpected expenses. I don't want anyone to hurt so I'd make sure they're covered in times of need, but extraordinary sums of money can do more harm than good.
Thereafter I'd ease into retirement from work and practice anonymous philanthropy for fully vetted causes.
And of course, buy an island and some really cool beach, trail and ocean crafts to escape to a few weeks each year!
It's up to $1,600,000,000 and I have a ticket.