The Roman numeral "CCCXXXI" represents the number 331. In this numeral, "CCC" stands for 300, as "C" equals 100, and there are three of them. The "XXX" represents 30, with each "X" equaling 10, and the "I" at the end adds 1. Roman numerals are a numeral system originating from ancient Rome. They are used in various contexts today, such as on clock faces, in book chapters, and for denoting years in historical events. Understanding Roman numerals can enhance one's appreciation of history and classical literature.