28685687 has 8 divisors (see below), whose sum is σ = 30898560. Its totient is φ = 26543160.

The previous prime is 28685659. The next prime is 28685711. The reversal of 28685687 is 78658682.

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

It is a cyclic number.

It is not a de Polignac number, because 28685687 - 2²⁴ = 11908471 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28681687) 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 7 ways as a sum of consecutive naturals, for example, 16739 + ... + 18372.

It is an arithmetic number, because the mean of its divisors is an integer number (3862320).

Almost surely, 2^28685687 is an apocalyptic number.

28685687 is a deficient number, since it is larger than the sum of its proper divisors (2212873).

28685687 is a wasteful number, since it uses less digits than its factorization.

28685687 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 35173.

The product of its digits is 1290240, while the sum is 50.

The square root of 28685687 is about 5355.9020715469. The cubic root of 28685687 is about 306.1176836707.

The spelling of 28685687 in words is "twenty-eight million, six hundred eighty-five thousand, six hundred eighty-seven".