Can anyone help me format my dollars data into millions of dollars for SQL Server?

3,000,000

--> $3M

I have this but it's not working

SELECT     '$' + SUM(Sales_Information.Sales_in_Dollars / 1000000) 
                      AS [Sales in Millions]

Doing this gives me #Error

format(SUM(Sales_Information.Sales_in_Dollars / 1000000)