867

867 is an integer that immediately follows 866 and precedes 868. In mathematics it is odd and composite, with prime factorization 3 × 17^2. Its divisors are 1, 3, 17, 51, 289, and 867. The digits sum to 21, so 867 is divisible by 3 but not by 9. In various numeral bases it is represented as follows: binary 1101100011, decimal 867, hexadecimal 0x363, and base-3 1012010_3; base-4 31203_4. In Roman numerals it is DCCCLXVII.

867 appears in popular culture, most notably as the prefix in the song 867-5309/Jenny, released in 1981, which popularized the sequence. In telecommunications, 867 is the area code used in Canada for the North American Numbering Plan region comprising Yukon, Northwest Territories, and Nunavut, with some northern portions of British Columbia overlapping.

As a year, 867 CE falls in the early medieval period and is used in historical timelines to denote events or contexts from that era. The number is also of interest in recreational mathematics and number representation, illustrating how a single integer can be described in multiple bases and numeral systems.