28509875 has 16 divisors (see below), whose sum is σ = 36173280. Its totient is φ = 22428000.

The previous prime is 28509851. The next prime is 28509889. The reversal of 28509875 is 57890582.

It is not a de Polignac number, because 28509875 - 2⁸ = 28509619 is a prime.

It is a Smith number, since the sum of its digits (44) coincides with the sum of the digits of its prime factors.

It is an unprimeable number.

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 15 ways as a sum of consecutive naturals, for example, 5756 + ... + 9494.

It is an arithmetic number, because the mean of its divisors is an integer number (2260830).

Almost surely, 2^28509875 is an apocalyptic number.

28509875 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

28509875 is a deficient number, since it is larger than the sum of its proper divisors (7663405).

28509875 is an equidigital number, since it uses as much as digits as its factorization.

28509875 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3815 (or 3805 counting only the distinct ones).

The product of its (nonzero) digits is 201600, while the sum is 44.

The square root of 28509875 is about 5339.4639244029. The cubic root of 28509875 is about 305.4910123851.

The spelling of 28509875 in words is "twenty-eight million, five hundred nine thousand, eight hundred seventy-five".