28787904 has 168 divisors, whose sum is σ = 89867232. Its totient is φ = 8785920.

The previous prime is 28787903. The next prime is 28787909. The reversal of 28787904 is 40978782.

It is a self number, because there is not a number n which added to its sum of digits gives 28787904.

It is not an unprimeable number, because it can be changed into a prime (28787903) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 543142 + ... + 543194.

It is an arithmetic number, because the mean of its divisors is an integer number (534924).

Almost surely, 2^28787904 is an apocalyptic number.

28787904 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 28787904, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (44933616).

28787904 is an abundant number, since it is smaller than the sum of its proper divisors (61079328).

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

28787904 is a wasteful number, since it uses less digits than its factorization.

28787904 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 135 (or 122 counting only the distinct ones).

The product of its (nonzero) digits is 225792, while the sum is 45.

The square root of 28787904 is about 5365.4360493813. The cubic root of 28787904 is about 306.4808536199.

The spelling of 28787904 in words is "twenty-eight million, seven hundred eighty-seven thousand, nine hundred four".