Pretend the $20 million is guaranteed, and if anything will increase slightly over time.
What problems could be significantly improved for $20 million?
(I am dreaming of winning the $1.55 billion Powerball drawling. Then taking the lumpsum, posting taxes, investing, and spending 4% each and every year. I understand that the actual may be more, or less than the started amount.)
Tell no one. Start some form of charitable institution anonymously to divert the majority to. Try not to become an idle leech or get murdered.