If you want to live without a worry I'd work to get double that amount, BTC33,670!
That is good count.
But it is dangerous to keep the amount in bitcoin when you retire.
You never know that one day the price goes down and down ...
It's a bit risky to let everything in BTC. I should sell a big part for dollars. You never know.
Wowha that is a bit extreme to say you need 5,000,000 then to double it lol! You do not need nowhere near that amount in 90% of the world obviously depending on your retirement age plays a big part but who would want to hoard anywhere near that amount to be dead in a few years>?
If you have that much you already have your home paid for cars furniture, holidays etc so what is a middle age- old age man or female going to spend 5,000,000 on?
They would never get threw it imo and to answer the original post who knows, i mean 100 might be enough 1000 could be where is the price going to be by the time i retire, i will make a guess and a goal of holding at least 1000