905

905 is a natural number that lies between 904 and 906. In mathematics, it is an odd semiprime, being the product of two primes: 5 and 181. Its divisors are 1, 5, 181, and 905. The sum of its digits is 14, so it is not divisible by 3. In Roman numerals it is written as CMV, and in binary it is 1110001001_2.

As a telephone area code, 905 is one of the area codes for Southern Ontario, Canada. It originally covered the outer ring around Toronto, excluding the city itself (416). In 1993 Bell Canada introduced 905 to the region; later overlays 289 and 365 were added, leading to ten-digit dialing in the area. The 905 region includes cities such as Hamilton, Oakville, Burlington, Mississauga, Brampton, and parts of York and Halton regions.

In Canadian popular culture and telecommunications, 905 is commonly referenced as a defining identifier of the suburban belt surrounding Toronto; residents of this region are sometimes colloquially called “the 905” or “905ers.”