9873

The number 9873 is a four-digit integer that appears in various contexts across mathematics, computing, and popular culture. In mathematics, 9873 is an odd composite number, meaning it is not a prime number and can be factored into smaller integers. Its prime factorization is 3 × 3 × 11 × 101, indicating that it is divisible by 3, 11, and 101. The number is also a Harshad number, as it is divisible by the sum of its digits (9 + 8 + 7 + 3 = 27, and 9873 ÷ 27 = 365.666..., though this is incorrect; the correct sum is 27, but 9873 ÷ 27 = 365.666..., which is not an integer, so it is not a Harshad number).

In computing, 9873 is sometimes referenced in programming challenges or puzzles, particularly in contexts involving binary or hexadecimal representations. For example, in binary, 9873 is represented as 10011001110101, while in hexadecimal, it is 25B5. It may also appear in error codes or checksums in certain software applications.

The number has gained minor notoriety in popular culture due to its appearance in the 2004 film *The Day After Tomorrow*, where it is referenced as a potential future date in a fictional climate disaster scenario. Additionally, it has been used in various internet memes, puzzles, and trivia questions, often due to its unusual combination of digits.

While 9873 lacks widespread significance, its appearance in different fields highlights how numbers can carry meaning beyond their numerical value. Its study remains of interest in recreational mathematics and computational puzzles.