28689187 has 4 divisors (see below), whose sum is σ = 28702296. Its totient is φ = 28676080.

The previous prime is 28689181. The next prime is 28689197. The reversal of 28689187 is 78198682.

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 28689187 - 2³ = 28689179 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 28689187.

It is not an unprimeable number, because it can be changed into a prime (28689181) 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 3 ways as a sum of consecutive naturals, for example, 2389 + ... + 7942.

It is an arithmetic number, because the mean of its divisors is an integer number (7175574).

Almost surely, 2^28689187 is an apocalyptic number.

28689187 is a deficient number, since it is larger than the sum of its proper divisors (13109).

28689187 is a wasteful number, since it uses less digits than its factorization.

28689187 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13108.

The product of its digits is 387072, while the sum is 49.

The square root of 28689187 is about 5356.2288039254. The cubic root of 28689187 is about 306.1301331817.

The spelling of 28689187 in words is "twenty-eight million, six hundred eighty-nine thousand, one hundred eighty-seven".