674 functions both as a natural number and as a calendar year designation. As a number it lies between 673 and 675 and has elementary arithmetical properties that make it straightforward to describe. When written as a year, 674 normally refers to AD 674 in the Julian calendar and is associated with events of the early medieval period across Europe, the Near East and East Asia.

Mathematical properties

674 is an even, composite integer. Its prime factorization is 2 × 337, with 337 being a prime number. The positive divisors of 674 are 1, 2, 337 and 674, so it has four positive divisors in total. The sum of all divisors is 1,014 and the sum of proper divisors (excluding the number itself) is 340, which is less than 674; therefore 674 is classified as a deficient number. As a product of two primes it is a semiprime (specifically, twice a prime).

Representations and notation

  • Decimal: 674
  • Binary: 1010100010
  • Octal: 1242
  • Hexadecimal: 2A2
  • Roman numerals: DCLXXIV

Year AD 674: historical context

The year AD 674 falls within the early Middle Ages. One of the best known associations with this year is the beginning, around 674, of sustained military operations by the Umayyad Caliphate against the Byzantine Empire that are commonly dated to c. 674–678 and include the first long-lived siege operations directed at Constantinople. These campaigns involved naval as well as land forces and formed part of the wider Arab–Byzantine conflicts of the seventh century. The Byzantine emperor at the time, Constantine IV, is notable for his role in organizing the defence of the capital during these years. In other regions, the same period saw ongoing political and religious developments characteristic of the Asuka period in Japan, the consolidations of various early medieval polities in Europe, and continuing state formation across the Near East.

Other usages and disambiguation

Outside arithmetic and chronology, the sequence "674" may appear as a label, catalogue number, model identifier, street or route number, or part of coded designations. In historical writing the year is typically qualified as AD 674 or 674 BC to avoid confusion with the bare numeral. When used in technical or cataloguing contexts it carries no intrinsic meaning beyond its function as an identifier.