What is 10000 in roman numerals?

In Roman numerals, the number 10000 is represented as "X̄" or sometimes as "MMMMMMMMMM". The use of a horizontal line placed above the Roman numeral "X" indicates multiplication by a thousand, thus representing the value of ten thousand.

It is worth noting that the Roman numeral system primarily used letters to represent numbers, with specific values assigned to each letter. The letter "X" represents the value 10 in Roman numerals, and by placing the horizontal line above it, the value is multiplied by a thousand, resulting in a representation of 10000.