28065564 has 18 divisors (see below), whose sum is σ = 70943600. Its totient is φ = 9355176.

The previous prime is 28065539. The next prime is 28065581. The reversal of 28065564 is 46556082.

It is a tau number, because it is divible by the number of its divisors (18).

It is a Harshad number since it is a multiple of its sum of digits (36), and also a Moran number because the ratio is a prime number: 779599 = 28065564 / (2 + 8 + 0 + 6 + 5 + 5 + 6 + 4).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 389764 + ... + 389835.

Almost surely, 2^28065564 is an apocalyptic number.

It is an amenable number.

28065564 is an abundant number, since it is smaller than the sum of its proper divisors (42878036).

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

28065564 is a wasteful number, since it uses less digits than its factorization.

28065564 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 779609 (or 779604 counting only the distinct ones).

The product of its (nonzero) digits is 57600, while the sum is 36.

The square root of 28065564 is about 5297.6942154111. The cubic root of 28065564 is about 303.8957254328.

The spelling of 28065564 in words is "twenty-eight million, sixty-five thousand, five hundred sixty-four".