1000 (Number)

1000 is a natural number that comes after 999 and before 1001. In Somali, it is called kun, with the plural forms kumaan or kunno. In the decimal numbering system, it is written as 10³, meaning ten to the power of three.

1000 serves as a standard threshold for grouping large numbers in their written form. Many international systems, including SI units of measurement, use 1000 as a base: kilo (kilo) means one thousand, so a kilometre is one thousand metres, and a kilogramme is one thousand grammes.

Mathematical properties

1000 is a composite number, meaning it has divisors other than 1 and itself. Its prime factorization is 2³ × 5³. It is also the cube of 10 (10 × 10 × 10). Its divisors are 1, 2, 4, 5, 8, 10, 20, 25, 40, 50, 100, 125, 200, 250, 500, and 1000.

Notation and symbols

In Roman numerals, 1000 is represented by the letter M. In modern Arabic numerals, it is written as ١٠٠٠. When writing large numbers, many languages separate digits in groups of three using a comma, full stop, or space—for example, 1,000 or 1 000.

Common uses

1000 is significant in currency systems, counting, and measurement. In computing, the term 'kilo' is sometimes used to mean 1024 (2¹⁰) rather than 1000, which has led to distinct notations such as kibibyte (KiB) for 1024 and kilobyte (kB) for 1000.