6404 has 6 divisors (see below), whose sum is σ = 11214. Its totient is φ = 3200.

The previous prime is 6397. The next prime is 6421. The reversal of 6404 is 4046.

It is a happy number.

It can be written as a sum of positive squares in only one way, i.e., 6400 + 4 = 80^2 + 2^2 .

It is a super-2 number, since 2×6404² = 82022432, which contains 22 as substring.

It is a plaindrome in base 7.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 797 + ... + 804.

It is an arithmetic number, because the mean of its divisors is an integer number (1869).

2⁶⁴⁰⁴ is an apocalyptic number.

It is an amenable number.

6404 is a deficient number, since it is larger than the sum of its proper divisors (4810).

6404 is a wasteful number, since it uses less digits than its factorization.

6404 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1605 (or 1603 counting only the distinct ones).

The product of its (nonzero) digits is 96, while the sum is 14.

The square root of 6404 is about 80.0249960950. The cubic root of 6404 is about 18.5702225196.

The spelling of 6404 in words is "six thousand, four hundred four".