28089564 has 12 divisors (see below), whose sum is σ = 65542344. Its totient is φ = 9363184.

The previous prime is 28089553. The next prime is 28089569. The reversal of 28089564 is 46598082.

It is a tau number, because it is divible by the number of its divisors (12).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28089569) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1170387 + ... + 1170410.

It is an arithmetic number, because the mean of its divisors is an integer number (5461862).

Almost surely, 2^28089564 is an apocalyptic number.

It is an amenable number.

28089564 is an abundant number, since it is smaller than the sum of its proper divisors (37452780).

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

28089564 is a wasteful number, since it uses less digits than its factorization.

28089564 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2340804 (or 2340802 counting only the distinct ones).

The product of its (nonzero) digits is 138240, while the sum is 42.

The square root of 28089564 is about 5299.9588677649. The cubic root of 28089564 is about 303.9823252651.

The spelling of 28089564 in words is "twenty-eight million, eighty-nine thousand, five hundred sixty-four".