Number
509 in Roman numerals
509 is written DIX
Type any other number or numeral below to convert it.
Above 3,999? Type the barred part in brackets, e.g. (IV)CC = 4,200.
How DIX is built
Roman numerals are written one decimal place at a time, largest first.
- Dhundreds · 5D is 500.
- IXones · 9I before X means 10 − 1 = 9. This saves writing VIIII.
500 + 9 = 509
The pair IX uses subtraction: a smaller letter before a larger one is taken away from it. Only six pairs work this way: IV, IX, XL, XC, CD and CM. More on subtraction
Mistakes to avoid
- Not DVIIII (6 letters). That adds everything up without subtraction. The Romans sometimes wrote numbers this way, and clocks still show 4 as IIII, but today DIX (3 letters) is the standard.
- There's no letter for zero. The zero is simply left out, which is why 509 has 2 parts, not 3.
About the number 509
- 509 is a prime number: only 1 and 509 divide it exactly.
- DIX has 3 letters. 907 of the numbers up to 1,000 have longer numerals.
Counting from 501 to 510
| Number | Roman numeral |
|---|---|
| 501 | DI |
| 502 | DII |
| 503 | DIII |
| 504 | DIV |
| 505 | DV |
| 506 | DVI |
| 507 | DVII |
| 508 | DVIII |
| 509 | DIX |
| 510 | DX |