CXXXI is the Roman numeral representation for the number 131. 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 "I" for 1. Therefore, CXXXI is calculated as 100 + 30 + 1, which equals 131. The use of Roman numerals can be found in various contexts, such as on clock faces, in book chapters, and in the naming of monarchs and popes. For example, Pope John Paul II is often referred to as John Paul II in Roman numeral form. This numeral system remains a part of cultural and historical references today.