CCLXXX

CCLXXX is the Roman numeral for the number 280. It is formed by adding the values of C (100) + C (100) + L (50) + X (10) + X (10) + X (10). In standard Roman numeral notation, when a smaller value follows a larger value, the values are added, so CCLXXX represents 280 without any subtraction.

In mathematics, 280 is a composite number with prime factorization 2^3 × 5 × 7. Its positive divisors include 1, 2, 4, 5, 7, 8, 10, 14, 20, 28, 35, 40, 56, 70, 140, and 280.

In other numeral systems, 280 equals 0x118 in hexadecimal, 100011000 in binary, and 430 in octal. These representations illustrate how the same value is expressed differently across numeral bases.

Usage of the numeral CCLXXX appears primarily in contexts that employ Roman numerals, such as historical inscriptions, classical texts, clocks, or chapter and volume designations. It may be encountered when referring to the year 280 CE in historical chronology, or to other enumerative labels that rely on Roman numerals. As a relatively small and even number, 280 also serves as a straightforward example of additive Roman notation without subtractive conventions.