823

823 is a natural number that comes after 822 and before 824. In mathematics it is an odd prime number, meaning it has no positive divisors other than 1 and itself. It can also be expressed as the sum of two consecutive integers: 411 plus 412 equals 823, illustrating the general fact that any odd number greater than 1 can be written as the sum of two consecutive integers.

In different numeral systems, 823 has distinct representations: in binary it is 1100110111, in hexadecimal it is 0x337, and in Roman numerals it is written as DCCCXXIII.

As a calendar year, 823 may denote a year in the Anno Domini era on the Julian or Gregorian calendars, depending on historical and regional contexts. Like other years, it is associated with whatever events are documented in sources that cover the early medieval period, though specific events vary by region and historiography.

In common usage, 823 also appears as an identifying number in various systems, such as catalog codes, route numbers, or product model designations. Without additional context, its meaning is purely numerical rather than inherently symbolic.