CDXXIV

CDXXIV is a Roman numeral representing the number 424. It is composed of CD (400) plus XX (20) plus IV (4): 400 + 20 + 4 equals 424. The CD portion uses subtractive notation, where C before D indicates 400 (500 minus 100), and IV uses subtractive notation to make 4, while XX contributes 20 additively.

In usage, CDXXIV can appear in dating historical events, numbering items, or labeling sections in documents that employ Roman numerals. It may also serve as a catalog or sequence identifier in educational materials or literature. Numerically, 424 is an even composite number: 424 = 8 × 53, or 2^3 × 53.

If used to denote a year, 424 CE falls in the mid-5th century, within the broader period of late antiquity. In inscriptions, manuscripts, or chronologies that preserve Roman numbering, CDXXIV functions as a conventional representation of the quantity or year it denotes. As with other Roman numerals, the form is primarily of historical and typographical interest in modern contexts, where Arabic numerals are more common for everyday counting.