Pumpi, the best advice anyone can give someone who wins money is to contact an attorney or financial advisor you trust. I'm not talking about picking up the phone and calling a place listed in the Yellow Pages. I mean to find out who counsels the rich. Once you have money, everyone wants to help you, so it might not be as difficult as it sounds.
Most people don't want to pay taxes on interest if they don't have to, so they look for tax deferred investments. Let's say you buy government bonds or an annuity. You might get a lower rate of return, but if you are in a very high tax bracket, you'll end up getting more than in a bank account because they are tax deferred. If you don't have one already, the first thing is to make sure you have the maximum allowable in an IRA and add to it every year. In any tax deferred account, the interest grows without a tax burden for years. Why pay tax on money you're not using? Of course any interest withdrawn later on is taxed. Again, a good attorney and financial planner would help you set up these investments. I've taken lots of courses and still wouldn't be able to handle millions of dollars at this point. Someone recently spoke to me about an extensive, ongoing training program for this very thing, that is, to learn how to help people protect their wealth. It's not easy to simply say "do this" or "do that." It takes years of experience.
I don't know what kind of interest a person would get on a million dollars if he decided to just place it in a bank. It wouldn't be FDIC insured anyway. Banks offer different rates depending on the amount you invest and the length of the term. So if you have $10,000 and buy a Certificate of Deposit (CD) for 1 year and get 5.1%, the same bank might offer you 5.5% if you buy a 3 year CD and so on. If you have $100,000 you will get a higher rate. Of course the bank can't break any federal regulations and it cannot afford to pay a rate higher than what it's earning by investing your money. They are in business to make a profit. As you know, the money isn't sitting in the bank. It's used for mortgages, personal loans, etc. The more money they get from depositors the more they can invest.
I've always wondered about offshore banks like Millenium Bank (MLNbank) I wonder how safe it is to invest your money. They've always had great interest rates on CDs and still offer the highest I've seen on the internet, but I'd contact an international lawyer or specialist in these matters before I ever invested my money out of the United States. Many people with a lot of money have offshore accounts. I believe Federal Law dictates you are still supposed to claim interest earned to the IRS, but they've been used as tax havens for years, especially places like Switzerland and the Caymen Islands.