8404 has 12 divisors (see below), whose sum is σ = 16128. Its totient is φ = 3800.

The previous prime is 8389. The next prime is 8419. The reversal of 8404 is 4048.

It is an interprime number because it is at equal distance from previous prime (8389) and next prime (8419).

It is an Ulam number.

It is a plaindrome in base 7 and base 9.

It is a congruent number.

It is an unprimeable number.

8404 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a pernicious number, because its binary representation contains a prime number (5) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 52 + ... + 139.

It is an arithmetic number, because the mean of its divisors is an integer number (1344).

2⁸⁴⁰⁴ is an apocalyptic number.

It is an amenable number.

8404 is a deficient number, since it is larger than the sum of its proper divisors (7724).

8404 is a wasteful number, since it uses less digits than its factorization.

8404 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 206 (or 204 counting only the distinct ones).

The product of its (nonzero) digits is 128, while the sum is 16.

The square root of 8404 is about 91.6733330909. The cubic root of 8404 is about 20.3311532794.

Subtracting from 8404 its reverse (4048), we obtain a square (4356 = 66²).

The spelling of 8404 in words is "eight thousand, four hundred four".