Millionaire

A millionaire (originally and sometimes still millionaire) is a person whose net worth (or wealth) is at least one million units of a currency (most of the times it will be U.S. dollar). As of 2012, millionaires were on average 61 years old with $3.05 million in value. This includes things like the stock market or real estate, not just money.
In June 2020, there were 13 million people in the world who are classified as U.S.-dollar millionaires.
Another commonly used term is multimillionaire. This is used to call a persona having two or more millions of assets. In financial world the word multimillionaire is used to categorize person with $30 million of assets or more. They are also called high net worth individuals (or HNWIs). 
America alone has 4,700,000 million HNWIs, with New York city having the most (an impressive total of 348,000 of them). Geneva has the highest density of super wealthy people per person in the world. 
By country.
Below is a list of millionaires per country according to Credit Suisse.