28517904 has 60 divisors (see below), whose sum is σ = 82574700. Its totient is φ = 9176832.

The previous prime is 28517899. The next prime is 28517911. The reversal of 28517904 is 40971582.

It can be written as a sum of positive squares in 2 ways, for example, as 15210000 + 13307904 = 3900^2 + 3648^2 .

It is a Harshad number since it is a multiple of its sum of digits (36).

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 762 + ... + 7590.

It is an arithmetic number, because the mean of its divisors is an integer number (1376245).

Almost surely, 2^28517904 is an apocalyptic number.

28517904 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 28517904, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (41287350).

28517904 is an abundant number, since it is smaller than the sum of its proper divisors (54056796).

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

28517904 is a wasteful number, since it uses less digits than its factorization.

28517904 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6872 (or 6863 counting only the distinct ones).

The product of its (nonzero) digits is 20160, while the sum is 36.

The square root of 28517904 is about 5340.2157259796. The cubic root of 28517904 is about 305.5196873281.

The spelling of 28517904 in words is "twenty-eight million, five hundred seventeen thousand, nine hundred four".