28112004 has 18 divisors (see below), whose sum is σ = 71060990. Its totient is φ = 9370656.

The previous prime is 28111997. The next prime is 28112011. The reversal of 28112004 is 40021182.

It is an interprime number because it is at equal distance from previous prime (28111997) and next prime (28112011).

It can be written as a sum of positive squares in only one way, i.e., 19713600 + 8398404 = 4440^2 + 2898^2 .

It is a tau number, because it is divible by the number of its divisors (18).

It is a Harshad number since it is a multiple of its sum of digits (18).

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 390409 + ... + 390480.

Almost surely, 2^28112004 is an apocalyptic number.

It is an amenable number.

28112004 is an abundant number, since it is smaller than the sum of its proper divisors (42948986).

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

28112004 is a wasteful number, since it uses less digits than its factorization.

28112004 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 780899 (or 780894 counting only the distinct ones).

The product of its (nonzero) digits is 128, while the sum is 18.

The square root of 28112004 is about 5302.0754426922. The cubic root of 28112004 is about 304.0632514971.

Adding to 28112004 its reverse (40021182), we get a palindrome (68133186).

The spelling of 28112004 in words is "twenty-eight million, one hundred twelve thousand, four".