28765687 has 4 divisors (see below), whose sum is σ = 29543176. Its totient is φ = 27988200.

The previous prime is 28765679. The next prime is 28765703. The reversal of 28765687 is 78656782.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 28765687 - 2³ = 28765679 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 28765687.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28765657) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 388689 + ... + 388762.

It is an arithmetic number, because the mean of its divisors is an integer number (7385794).

Almost surely, 2^28765687 is an apocalyptic number.

28765687 is a deficient number, since it is larger than the sum of its proper divisors (777489).

28765687 is an equidigital number, since it uses as much as digits as its factorization.

28765687 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 777488.

The product of its digits is 1128960, while the sum is 49.

The square root of 28765687 is about 5363.3652681875. The cubic root of 28765687 is about 306.4019913600.

The spelling of 28765687 in words is "twenty-eight million, seven hundred sixty-five thousand, six hundred eighty-seven".