622

622 is a natural number that comes after 621 and before 623. In mathematics, it is an even composite number. Its prime factorization is 2 × 311, with 311 prime. It is not a square or a cube. In various numeral systems, 622 is written as 1001101110 in binary, 1156 in octal, 26E in hexadecimal, and DCXXII in Roman numerals.

The year 622 CE is historically significant in world history: The Hijra, the migration of the Prophet Muhammad and his followers from Mecca to Medina, occurred in 622 CE. This event is date-labeled as the start of the Islamic calendar, year 1 AH.

In other uses, 622 may appear as a model number or identifier in products and vehicles, or as a numerical label in various catalogs.