28256865 has 64 divisors (see below), whose sum is σ = 56426496. Its totient is φ = 11757312.

The previous prime is 28256861. The next prime is 28256867. The reversal of 28256865 is 56865282.

It is not a de Polignac number, because 28256865 - 2² = 28256861 is a prime.

It is not an unprimeable number, because it can be changed into a prime (28256861) 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 63 ways as a sum of consecutive naturals, for example, 173274 + ... + 173436.

It is an arithmetic number, because the mean of its divisors is an integer number (881664).

Almost surely, 2^28256865 is an apocalyptic number.

It is an amenable number.

28256865 is a deficient number, since it is larger than the sum of its proper divisors (28169631).

28256865 is a wasteful number, since it uses less digits than its factorization.

28256865 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 318.

The product of its digits is 230400, while the sum is 42.

The square root of 28256865 is about 5315.7186720142. The cubic root of 28256865 is about 304.5846357037.

The spelling of 28256865 in words is "twenty-eight million, two hundred fifty-six thousand, eight hundred sixty-five".