999 in Roman Numerals
999
C (subtracted)MX (subtracted)CI (subtracted)X
nine hundred ninety-nine
How CMXCIX is formed
| Place | Value | Symbols |
|---|---|---|
| Hundreds | 900 | C (subtracted)M |
| Tens | 90 | X (subtracted)C |
| Units | 9 | I (subtracted)X |
| Total | 999 | CMXCIX |
CMXCIX is written one place at a time, from the largest to the smallest: CM (900) + XC (90) + IX (9) = 999.
CM, XC, and IX are subtractive pairs: in each one the smaller symbol comes first and is taken away.
Common mistakes
Wrong: IM
Why isn't 999 written as IM?
I can only be subtracted from V and X, so IM (1000 − 1) is not a valid pair. Write each place separately: CM (900) + XC (90) + IX (9) = CMXCIX.
Wrong: CMIC
Why isn't 999 written as CMIC?
I can only be subtracted from V and X, so IC (100 − 1) is not a valid pair. Write each place separately: CM (900) + XC (90) + IX (9) = CMXCIX.
Wrong: DCCCCXCIX
Why isn't 999 written as DCCCCXCIX?
A symbol can't be repeated four times in a row. 900 is CM (1000 − 100), not DCCCC, so 999 is CMXCIX.
Numbers near 999
Properties of 999
- Prime factors
- 3³ × 37
- Divisors
- 1, 3, 9, 27, 37, 111, 333, 999
- Even or odd
- Odd
- Prime number
- No
- Letters in CMXCIX
- 6
999,000 in Roman numerals
With a bar over it (vinculum), C̅M̅X̅C̅I̅X̅ means 999 × 1,000 = 999,000. How Roman numerals work