Century 21 Real Estate LLC is a real estate agent franchise company founded in 1971. The Century 21 System consists of over 7,700 independently owned and operated offices. Other examples of such a system are Coldwell Banker, Engel & Vlkers, ERA Real Estate, ... Century 21 has offices in more than 68 countries and territories. Century 21's consumer website, Century21. com, is the fifth most visited real estate website on the Internet as of March 2009.