28328189 has 4 divisors (see below), whose sum is σ = 28339200. Its totient is φ = 28317180.

The previous prime is 28328173. The next prime is 28328191. The reversal of 28328189 is 98182382.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is not a de Polignac number, because 28328189 - 2⁴ = 28328173 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28348189) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 644 + ... + 7554.

It is an arithmetic number, because the mean of its divisors is an integer number (7084800).

Almost surely, 2^28328189 is an apocalyptic number.

It is an amenable number.

28328189 is a deficient number, since it is larger than the sum of its proper divisors (11011).

28328189 is an equidigital number, since it uses as much as digits as its factorization.

28328189 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11010.

The product of its digits is 55296, while the sum is 41.

The square root of 28328189 is about 5322.4232263134. The cubic root of 28328189 is about 304.8406907887.

The spelling of 28328189 in words is "twenty-eight million, three hundred twenty-eight thousand, one hundred eighty-nine".