There are very few in this Forum I would ask opinions on how to spread out 23 million, people generally offer advise based on them not caring in the least of capital accumulation.
I would divide 20 million and keep 3 million in short term CD's and savings over a few healthy banks.
then in 10 different investments of 2 million.
I wouldn't put much into stocks right now unless you can find 4% plus dividend with low debt.
I would hold off on real estate, it will get much worse before better, the higher interest rates one day will become, the cheaper properties will become.
Start learning about investing in properties and what value is. You can bid on Tax Lien notes on valued properties, get a bit more in interest and your money is secured by property, occassionally you will get properties. I do well in these and anyone can.
Gold and Silver rather high, so I would wait on buying coins, always buy as a collector. Some art paintings have been going low since bad economy, but you have to have good friends who know something about value. When you buy sports collectable items, make sure you have certificates to show they are real. Original Comic book first editions have been favorable past couple years.
If you know little about the markets, examine what they have done in past ten years and always look at the bad years, not the good years when it comes to no load mutual funds.
Check out some annutites, 5 years if they have them, interest rates will go up.
If you have never traded before, DON'T. And when in doubt, toss it in a few banks, into savings and stash a bunch into a safe.