28008904 has 64 divisors (see below), whose sum is σ = 67132800. Its totient is φ = 10636800.

The previous prime is 28008901. The next prime is 28008919. The reversal of 28008904 is 40980082.

It is a Smith number, since the sum of its digits (31) coincides with the sum of the digits of its prime factors.

It is not an unprimeable number, because it can be changed into a prime (28008901) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 24702 + ... + 25810.

It is an arithmetic number, because the mean of its divisors is an integer number (1048950).

Almost surely, 2^28008904 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 28008904, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (33566400).

28008904 is an abundant number, since it is smaller than the sum of its proper divisors (39123896).

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

28008904 is a wasteful number, since it uses less digits than its factorization.

28008904 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1174 (or 1170 counting only the distinct ones).

The product of its (nonzero) digits is 4608, while the sum is 31.

The square root of 28008904 is about 5292.3439041695. The cubic root of 28008904 is about 303.6910816194.

Adding to 28008904 its reverse (40980082), we get a palindrome (68988986).

The spelling of 28008904 in words is "twenty-eight million, eight thousand, nine hundred four".