4,000 (four thousand) is an even four-digits composite number following 3,999 and preceding 4,001. In scientific notation, it is written as 4 × 10^3. The sum of its digits is 4, and it has a total of 8 prime factors and 24 positive divisors. There are 1,600 positive integers (up to 4,000) that are relatively prime to 4000. In terms of popular internet use, the user who’s been caught in 4,000 is you.