1009

1009 is a natural number that follows 1008 and precedes 1010. It is a prime number, the 169th prime in the sequence of primes, and it is odd. In modular arithmetic it is congruent to 1 modulo 4, and it can be expressed as a sum of two squares: 1009 = 28^2 + 15^2. In Roman numerals, 1009 is written as MIX.

In the calendar, the year 1009 CE is noted for significant events in Jerusalem. Fatimid Caliph Al-Hakim bi-Amr Allah reportedly ordered the destruction of the Church of the Holy Sepulchre, an act that had lasting religious and political repercussions and contributed to tensions between Christian and Muslim communities, influencing the broader historical context of the era.

In astronomy, the number 1009 is associated with a minor planet. 1009 Sirene is a main-belt asteroid that was discovered in 1923 by Karl Reinmuth. As with many numbered asteroids, the designation reflects its order of discovery and cataloging, and it carries a name drawn from classical mythology.

As a numeral, 1009 is used in various counting, labeling, and classification systems where prime numbers often serve as identifiers or references. Its properties as a prime, its representation as MIX in Roman numerals, and its historical and astronomical associations give it a context beyond merely being a four-digit integer.