28565191 has 4 divisors (see below), whose sum is σ = 28576912. Its totient is φ = 28553472.

The previous prime is 28565179. The next prime is 28565209. The reversal of 28565191 is 19156582.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is not a de Polignac number, because 28565191 - 2⁷ = 28565063 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 28565191.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28565111) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 675 + ... + 7588.

It is an arithmetic number, because the mean of its divisors is an integer number (7144228).

Almost surely, 2^28565191 is an apocalyptic number.

28565191 is a deficient number, since it is larger than the sum of its proper divisors (11721).

28565191 is an equidigital number, since it uses as much as digits as its factorization.

28565191 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11720.

The product of its digits is 21600, while the sum is 37.

The square root of 28565191 is about 5344.6413350196. The cubic root of 28565191 is about 305.6884600359.

The spelling of 28565191 in words is "twenty-eight million, five hundred sixty-five thousand, one hundred ninety-one".