The number 21 is written as XXI in Roman numerals.
Roman numerals use seven symbols: I (1), V (5), X (10), L (50), C (100), D (500), and M (1000). Numbers are formed by combining symbols and adding their values. When a smaller symbol appears before a larger one, it is subtracted (e.g., IV = 4, IX = 9, XL = 40, XC = 90, CD = 400, CM = 900).
To convert 21: start with the largest possible symbol and subtract its value, repeating until the remainder is zero. The result is XXI.
| Number | Roman Numeral |
|---|---|
| 16 | XVI |
| 17 | XVII |
| 18 | XVIII |
| 19 | XIX |
| 20 | XX |
| 21 | XXI |
| 22 | XXII |
| 23 | XXIII |
| 24 | XXIV |
| 25 | XXV |
| 26 | XXVI |