CXXIII is the Roman numeral representation for the number 123. Roman numerals are a numeral system originating from ancient Rome, using combinations of letters from the Latin alphabet. In this system, "C" stands for 100, "X" for 10, and "III" for 3, which together add up to 123. This numeral can be found in various contexts, such as in the titles of books, movies, or even in the numbering of chapters and sections. Understanding Roman numerals, including CXXIII, can be useful in reading historical texts or in certain modern applications like clocks and legal documents.