28539191 has 4 divisors (see below), whose sum is σ = 28551072. Its totient is φ = 28527312.

The previous prime is 28539179. The next prime is 28539211. The reversal of 28539191 is 19193582.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-28539191 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 (28539101) 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, 926 + ... + 7611.

It is an arithmetic number, because the mean of its divisors is an integer number (7137768).

Almost surely, 2^28539191 is an apocalyptic number.

28539191 is a deficient number, since it is larger than the sum of its proper divisors (11881).

28539191 is an equidigital number, since it uses as much as digits as its factorization.

28539191 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11880.

The product of its digits is 19440, while the sum is 38.

The square root of 28539191 is about 5342.2084384644. The cubic root of 28539191 is about 305.5956861353.

The spelling of 28539191 in words is "twenty-eight million, five hundred thirty-nine thousand, one hundred ninety-one".