28189911 has 8 divisors (see below), whose sum is σ = 38116224. Its totient is φ = 18528440.

The previous prime is 28189891. The next prime is 28189921. The reversal of 28189911 is 11998182.

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 28189911 - 2¹⁰ = 28188887 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 28189911.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28189921) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 65961 + ... + 66386.

It is an arithmetic number, because the mean of its divisors is an integer number (4764528).

Almost surely, 2^28189911 is an apocalyptic number.

28189911 is a deficient number, since it is larger than the sum of its proper divisors (9926313).

28189911 is a wasteful number, since it uses less digits than its factorization.

28189911 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 132421.

The product of its digits is 10368, while the sum is 39.

The square root of 28189911 is about 5309.4171996557. The cubic root of 28189911 is about 304.3438766530.

The spelling of 28189911 in words is "twenty-eight million, one hundred eighty-nine thousand, nine hundred eleven".