406

406 is a natural number that follows 405 and precedes 407. It is an even composite number, with prime factorization 2 × 7 × 29. The sum of its digits is 10, and it is divisible by 2, 7, 29, and 406 itself.

In numerical representations, 406 in binary is 110010110, in hexadecimal it is 0x196, and in Roman numerals it is CDVI (400 = CD and 6 = VI).

Historically, in 406 CE a federation of Vandals, Suebi and Alans crossed the Rhine into Roman Gaul, entering the Western Roman Empire’s territories and triggering a wave of incursions across the region.

In modern computing, 406 Not Acceptable is an HTTP status code indicating that the server cannot deliver a response that the client deems acceptable according to its Accept headers. It is part of the standard set of client–server communication status codes used to convey specific error or success states.

Geographically, 406 is also the area code for the U.S. state of Montana, covering the entire state.