28185859 has 4 divisors (see below), whose sum is σ = 30354016. Its totient is φ = 26017704.

The previous prime is 28185841. The next prime is 28185907. The reversal of 28185859 is 95858182.

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 28185859 - 2⁵ = 28185827 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (28185259) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1084059 + ... + 1084084.

It is an arithmetic number, because the mean of its divisors is an integer number (7588504).

Almost surely, 2^28185859 is an apocalyptic number.

28185859 is a deficient number, since it is larger than the sum of its proper divisors (2168157).

28185859 is a wasteful number, since it uses less digits than its factorization.

28185859 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2168156.

The product of its digits is 230400, while the sum is 46.

The square root of 28185859 is about 5309.0355998053. The cubic root of 28185859 is about 304.3292938887.

The spelling of 28185859 in words is "twenty-eight million, one hundred eighty-five thousand, eight hundred fifty-nine".