840 in Roman Numerals
840
DCCCX (subtracted)L
eight hundred forty
How DCCCXL is formed
| Place | Value | Symbols |
|---|---|---|
| Hundreds | 800 | DCCC |
| Tens | 40 | X (subtracted)L |
| Total | 840 | DCCCXL |
DCCCXL is written one place at a time, from the largest to the smallest: DCCC (800) + XL (40) = 840.
XL is the only subtraction: the X before the L takes away 10, so XL = 40.
Common mistakes
Wrong: DCCCXXXX
Why isn't 840 written as DCCCXXXX?
A symbol can't be repeated four times in a row. 40 is XL (50 − 10), not XXXX, so 840 is DCCCXL.
Wrong: CCMXL
Why isn't 840 written as CCMXL?
Only one smaller symbol can stand before a larger one, so CCM doesn't work. 800 is DCCC (500 + 300), so 840 is DCCCXL.
Numbers near 840
Properties of 840
- Prime factors
- 2³ × 3 × 5 × 7
- Divisors
- 32 divisors1, 2, 3, 4 … 840
- Even or odd
- Even
- Prime number
- No
- Letters in DCCCXL
- 6
840,000 in Roman numerals
With a bar over it (vinculum), D̅C̅C̅C̅X̅L̅ means 840 × 1,000 = 840,000. How Roman numerals work