1000 (number)

Notation

• The decimal representation for one thousand is
• * 1000—a one followed by three zeros, in the general notation ;
• * 1 × 10³—in engineering notation, which for this number coincides with :
• * 1 × 10³ exactly—in scientific normalized exponential notation ;
• * 1 E+3 exactly—in scientific E notation.
• The SI prefix for a thousand units is "kilo-", abbreviated to "k"—for instance, a kilometre or "km" is a thousand metres.
• In the SI writing style, a non-breaking space can be used as a thousands separator, i.e., to separate the digits of a number at every power of 1000.
• Multiples of thousands are occasionally represented by replacing their last three zeros with the letter "K": for instance, writing "$30K" for $30 000, or denoting the Y2K computer bug of the year 2000.
• A thousand units of currency, especially dollars or pounds, are colloquially called a grand, which can be abbreviated with a "G" suffix.

  Properties

• 1000 is a Harshad number in base 10.
• The sum of Euler's totient function over the first 57 integers is 1000.
• mentions that 1000 is the smallest number that generates three primes in the fastest way possible by concatenation of decremented numbers. The criterion excludes counting the number itself.

  Selected numbers in the range 1001–1999

1001 to 1099

1100 to 1199

1200 to 1299

1300 to 1399

1400 to 1499

1500 to 1599

1600 to 1699

1700 to 1799

1800 to 1899

1900 to 1999