28289191 has 8 divisors (see below), whose sum is σ = 32651424. Its totient is φ = 24007200.

The previous prime is 28289167. The next prime is 28289231. The reversal of 28289191 is 19198282.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 28289191 - 2⁹ = 28288679 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 (28289161) 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, 19300 + ... + 20713.

It is an arithmetic number, because the mean of its divisors is an integer number (4081428).

Almost surely, 2^28289191 is an apocalyptic number.

28289191 is a deficient number, since it is larger than the sum of its proper divisors (4362233).

28289191 is a wasteful number, since it uses less digits than its factorization.

28289191 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 40121.

The product of its digits is 20736, while the sum is 40.

The square root of 28289191 is about 5318.7584077489. The cubic root of 28289191 is about 304.7007402408.

Subtracting from 28289191 its reverse (19198282), we obtain a palindrome (9090909).

The spelling of 28289191 in words is "twenty-eight million, two hundred eighty-nine thousand, one hundred ninety-one".