1000
Cardinal	One thousand
Ordinal	One thousandth
Factorization
Roman numeral	M
Binary	1111101000
Hexadecimal	3E8

In scientific notation, it is written as 10³. The SI prefix for a thousand is "kilo-".

The Roman numeral for thousand is M (for mille).

See also: millennium

Selected numbers in the thousands (1000-1999)

;1001 - sphenic number ;1002 - sphenic number ;1013 - Sophie Germain prime ;1019 - Sophie Germain prime ;1031 - Sophie Germain prime ;1035 - triangular number ;1049 - Sophie Germain prime ;1081 - triangular number ;1103 - Sophie Germain prime ;1104 - Keith number ;1128 - triangular number ;1176 - triangular number ;1223 - Sophie Germain prime ;1225 - triangular number ;1229 - Sophie Germain prime ;1260 - highly composite number ;1289 - Sophie Germain prime ;1326 - triangular number ;1378 - triangular number ;1409 - Sophie Germain prime ;1431 - triangular number ;1439 - Sophie Germain prime ;1451 - Sophie Germain prime ;1481 - Sophie Germain prime ;1485 - triangular number ;1499 - Sophie Germain prime ;1511 - Sophie Germain prime ;1537 - Keith number ;1540 - triangular number ;1559 - Sophie Germain prime ;1583 - Sophie Germain prime ;1596 - triangular number ;1597 - Fibonacci number ;1601 - Sophie Germain prime ;1653 - triangular number ;1680 - highly composite number ;1711 - triangular number ;1729 - taxicab number ;1733 - Sophie Germain prime ;1770 - triangular number ;1811 - Sophie Germain prime ;1830 - triangular number ;1889 - Sophie Germain prime ;1891 - triangular number ;1901 - Sophie Germain prime ;1931 - Sophie Germain prime ;1953 - triangular number ;1973 - Sophie Germain prime