28904 has 8 divisors (see below), whose sum is σ = 54210. Its totient is φ = 14448.

The previous prime is 28901. The next prime is 28909. The reversal of 28904 is 40982.

It can be written as a sum of positive squares in only one way, i.e., 28900 + 4 = 170^2 + 2^2 .

It is a tau number, because it is divible by the number of its divisors (8).

It is a plaindrome in base 12.

It is a self number, because there is not a number n which added to its sum of digits gives 28904.

It is not an unprimeable number, because it can be changed into a prime (28901) 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 as a sum of consecutive naturals, namely, 1799 + ... + 1814.

2²⁸⁹⁰⁴ is an apocalyptic number.

It is an amenable number.

28904 is a deficient number, since it is larger than the sum of its proper divisors (25306).

28904 is a wasteful number, since it uses less digits than its factorization.

28904 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3619 (or 3615 counting only the distinct ones).

The product of its (nonzero) digits is 576, while the sum is 23.

The square root of 28904 is about 170.0117642988. The cubic root of 28904 is about 30.6892293524.

The spelling of 28904 in words is "twenty-eight thousand, nine hundred four".