28756665 has 24 divisors (see below), whose sum is σ = 56966208. Its totient is φ = 13145760.

The previous prime is 28756657. The next prime is 28756667. The reversal of 28756665 is 56665782.

It is not a de Polignac number, because 28756665 - 2³ = 28756657 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a self number, because there is not a number n which added to its sum of digits gives 28756665.

It is not an unprimeable number, because it can be changed into a prime (28756667) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 45331 + ... + 45960.

It is an arithmetic number, because the mean of its divisors is an integer number (2373592).

Almost surely, 2^28756665 is an apocalyptic number.

It is an amenable number.

28756665 is a deficient number, since it is larger than the sum of its proper divisors (28209543).

28756665 is a wasteful number, since it uses less digits than its factorization.

28756665 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 91309 (or 91306 counting only the distinct ones).

The product of its digits is 604800, while the sum is 45.

The square root of 28756665 is about 5362.5241258199. The cubic root of 28756665 is about 306.3699549524.

The spelling of 28756665 in words is "twenty-eight million, seven hundred fifty-six thousand, six hundred sixty-five".