LXXXI is the Roman numeral representation for the number 81. Roman numerals are a numeral system originating from ancient Rome, using combinations of letters from the Latin alphabet. In this system, L stands for 50, X for 10, and I for 1. Therefore, LXXXI can be broken down as 50 + 30 + 1, which equals 81. The number 81 has various mathematical properties; it is a perfect square, as it is the square of 9 (9). Additionally, in the context of numerology, 81 can be reduced to the single digit 9, which is often associated with completion and humanitarianism.