21 in Roman Numerals

In Roman numerals, the number 21 is represented as XXI. This notation combines XX (20) and I (1), where I is placed after XX to indicate that 1 is added to 20. Therefore, XXI effectively means 20 plus 1, which equals 21.

How to Write 21 in Roman Numerals?

To write the number 21 in Roman numerals, follow these steps:

• Step 1: Identify the largest Roman numeral that is less than or equal to 21. In this case, it’s “XX,” which represents 20.
• Step 2: Since 21 is 1 more than 20, you need to add a smaller Roman numeral to a larger one. To represent 21, you add 1 to 20.
• Step 3: Write “I” (1) after “XX” (20), which gives you “XXI.”

So, the Roman numeral for 21 is “XXI.”

Roman Numeral Converter

Rules for Roman Numerals

• Basic Symbols: Roman numerals are composed of basic symbols to represent numbers: I (1), V (5), X (10), L (50), C (100), D (500), and M (1000).
• Repeated Symbols: If a Roman numeral has a symbol repeated, the values are added together. For example, III is 1 + 1 + 1 = 3.
• Subtractive Notation: When a smaller Roman numeral appears before a larger one, it is subtracted from the larger one. For example, IV represents 5 – 1 = 4.
• No More Than Three Repeats: A Roman numeral cannot have more than three consecutive identical symbols. Larger numbers are represented using subtractive notation.
• Order of Symbols: Roman numerals are read from left to right. Larger values should always come before smaller ones.

Roman Numerals Related to 21

• 19: XIX
• 20: XX
• 21: XXI
• 22: XXII
• 23: XXIII
• 24: XXIV
• 25: XXV