You say that you have 2mil usd and want to invest on bitcoin, then go ahead and invest it over there.

Where can I invest it?
You mean where can you buy it?
what exactly are you pertaining to invest? buying bitcoin or purchasing altcoins using bitcoins? if you want to buy bitcoins you can join communities of bitcoin fanatics in your location and you can find someone who is willing to sell it to you if now there is coinbase and the like to buy from, If you are pertaining in investing to altcoins you can put your bitcoin in exchange platforms like bittrex there you can buy altcoins using bitcoin if you are just starting buying the major coins is a good choice and learning the indicator and patterns in trading is also a big help