28009656 has 24 divisors (see below), whose sum is σ = 75859680. Its totient is φ = 9336528.

The previous prime is 28009637. The next prime is 28009661. The reversal of 28009656 is 65690082.

It is a tau number, because it is divible by the number of its divisors (24).

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

It is a self number, because there is not a number n which added to its sum of digits gives 28009656.

It is a congruent number.

It is an unprimeable number.

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 5 ways as a sum of consecutive naturals, for example, 194440 + ... + 194583.

It is an arithmetic number, because the mean of its divisors is an integer number (3160820).

Almost surely, 2^28009656 is an apocalyptic number.

It is an amenable number.

28009656 is an abundant number, since it is smaller than the sum of its proper divisors (47850024).

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

28009656 is a wasteful number, since it uses less digits than its factorization.

28009656 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 389035 (or 389028 counting only the distinct ones).

The product of its (nonzero) digits is 25920, while the sum is 36.

The square root of 28009656 is about 5292.4149497181. The cubic root of 28009656 is about 303.6937994890.

The spelling of 28009656 in words is "twenty-eight million, nine thousand, six hundred fifty-six".