First: Congrats on your accomplishments!
As you'll see by poking around here, 4% is considered to be a safe withdrawal rate (SWR) when invested in the stock market index. 4% of 5,000,000 is $200,000, so you're easily set, even if you only invested in the index. Unless you are willing to actively manage rental real estate and perhaps do some maintenance (because you want to?), rental real estate returns, statistically, are in the 6-8% range. If you're willing to spend the time to look for deals and use leverage, then you can easily crush the average in real estate.
But if you're going truly passive, I'd follow MMM's recommendation on index funds, dividend index funds, reit's, and maybe some low key local real estate.