LXXIII is the Roman numeral representation for the number 73. 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 III for 3, which together add up to 73. The number 73 has significance in various fields, including mathematics and science. For example, it is a prime number, meaning it is only divisible by 1 and itself. Additionally, in the context of chemistry, 73 is the atomic number of tantalum, a rare metal used in electronics and other applications.