28104640 has 56 divisors (see below), whose sum is σ = 67921632. Its totient is φ = 11074560.

The previous prime is 28104619. The next prime is 28104647. The reversal of 28104640 is 4640182.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28104647) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 22102 + ... + 23338.

Almost surely, 2^28104640 is an apocalyptic number.

28104640 is a gapful number since it is divisible by the number (20) 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 28104640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (33960816).

28104640 is an abundant number, since it is smaller than the sum of its proper divisors (39816992).

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

28104640 is a wasteful number, since it uses less digits than its factorization.

28104640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1325 (or 1315 counting only the distinct ones).

The product of its (nonzero) digits is 1536, while the sum is 25.

The square root of 28104640 is about 5301.3809521671. The cubic root of 28104640 is about 304.0366991706.

The spelling of 28104640 in words is "twenty-eight million, one hundred four thousand, six hundred forty".