28564638 has 32 divisors (see below), whose sum is σ = 60397440. Its totient is φ = 8981280.

The previous prime is 28564621. The next prime is 28564687. The reversal of 28564638 is 83646582.

It is a self number, because there is not a number n which added to its sum of digits gives 28564638.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 37356 + ... + 38112.

It is an arithmetic number, because the mean of its divisors is an integer number (1887420).

Almost surely, 2^28564638 is an apocalyptic number.

28564638 is an abundant number, since it is smaller than the sum of its proper divisors (31832802).

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

28564638 is a wasteful number, since it uses less digits than its factorization.

28564638 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1112.

The product of its digits is 276480, while the sum is 42.

The square root of 28564638 is about 5344.5896007084. The cubic root of 28564638 is about 305.6864873925.

The spelling of 28564638 in words is "twenty-eight million, five hundred sixty-four thousand, six hundred thirty-eight".