2004 has 12 divisors (see below), whose sum is σ = 4704. Its totient is φ = 664.

The previous prime is 2003. The next prime is 2011. The reversal of 2004 is 4002.

2004 = T₅ + T₆ + ... + T₂₂.

It is a tau number, because it is divible by the number of its divisors (12).

It is a Harshad number since it is a multiple of its sum of digits (6).

It is a super Niven number, because it is divisible the sum of any subset of its (nonzero) digits.

It is a plaindrome in base 9.

It is a nialpdrome in base 13 and base 14.

It is a junction number, because it is equal to n+sod(n) for n = 1983 and 2001.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2003) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 72 + ... + 95.

It is an arithmetic number, because the mean of its divisors is an integer number (392).

2²⁰⁰⁴ is an apocalyptic number.

It is an amenable number.

2004 is an abundant number, since it is smaller than the sum of its proper divisors (2700).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

It is a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2352).

2004 is a wasteful number, since it uses less digits than its factorization.

2004 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 174 (or 172 counting only the distinct ones).

The product of its (nonzero) digits is 8, while the sum is 6.

The square root of 2004 is about 44.7660585712. The cubic root of 2004 is about 12.6076043792.

Adding to 2004 its reverse (4002), we get a palindrome (6006).

The spelling of 2004 in words is "two thousand, four", and thus it is an eban number and an iban number.