28775565 has 48 divisors (see below), whose sum is σ = 61396608. Its totient is φ = 12140928.

The previous prime is 28775521. The next prime is 28775573. The reversal of 28775565 is 56557782.

28775565 is a `hidden beast` number, since 2 + 87 + 7 + 5 + 565 = 666.

It is not a de Polignac number, because 28775565 - 2⁹ = 28775053 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 28775565.

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 47 ways as a sum of consecutive naturals, for example, 582 + ... + 7608.

It is an arithmetic number, because the mean of its divisors is an integer number (1279096).

Almost surely, 2^28775565 is an apocalyptic number.

It is an amenable number.

28775565 is an abundant number, since it is smaller than the sum of its proper divisors (32621043).

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

28775565 is a wasteful number, since it uses less digits than its factorization.

28775565 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7058 (or 7055 counting only the distinct ones).

The product of its digits is 588000, while the sum is 45.

The square root of 28775565 is about 5364.2860661974. The cubic root of 28775565 is about 306.4370596747.

The spelling of 28775565 in words is "twenty-eight million, seven hundred seventy-five thousand, five hundred sixty-five".