28289904 has 80 divisors (see below), whose sum is σ = 79557408. Its totient is φ = 8626176.

The previous prime is 28289903. The next prime is 28289927. The reversal of 28289904 is 40998282.

It is a hoax number, since the sum of its digits (42) coincides with the sum of the digits of its distinct prime factors.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28289903) 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, 29724 + ... + 30660.

Almost surely, 2^28289904 is an apocalyptic number.

28289904 is a gapful number since it is divisible by the number (24) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 28289904, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (39778704).

28289904 is an abundant number, since it is smaller than the sum of its proper divisors (51267504).

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

28289904 is a wasteful number, since it uses less digits than its factorization.

28289904 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1002 (or 996 counting only the distinct ones).

The product of its (nonzero) digits is 82944, while the sum is 42.

The square root of 28289904 is about 5318.8254342477. The cubic root of 28289904 is about 304.7033001090.

The spelling of 28289904 in words is "twenty-eight million, two hundred eighty-nine thousand, nine hundred four".