28520665 has 8 divisors (see below), whose sum is σ = 34486848. Its totient is φ = 22641840.

The previous prime is 28520641. The next prime is 28520669. The reversal of 28520665 is 56602582.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 28520665 - 2⁵ = 28520633 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 28520665.

It is not an unprimeable number, because it can be changed into a prime (28520669) 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 7 ways as a sum of consecutive naturals, for example, 21117 + ... + 22426.

It is an arithmetic number, because the mean of its divisors is an integer number (4310856).

Almost surely, 2^28520665 is an apocalyptic number.

It is an amenable number.

28520665 is a deficient number, since it is larger than the sum of its proper divisors (5966183).

28520665 is a wasteful number, since it uses less digits than its factorization.

28520665 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 43679.

The product of its (nonzero) digits is 28800, while the sum is 34.

The square root of 28520665 is about 5340.4742298788. The cubic root of 28520665 is about 305.5295467792.

The spelling of 28520665 in words is "twenty-eight million, five hundred twenty thousand, six hundred sixty-five".