28689191 has 4 divisors (see below), whose sum is σ = 28716672. Its totient is φ = 28661712.

The previous prime is 28689181. The next prime is 28689197. The reversal of 28689191 is 19198682.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 19198682 = 2 ⋅9599341.

It is a cyclic number.

It is not a de Polignac number, because 28689191 - 2¹⁰ = 28688167 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 (28689197) 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, 12110 + ... + 14283.

It is an arithmetic number, because the mean of its divisors is an integer number (7179168).

Almost surely, 2^28689191 is an apocalyptic number.

28689191 is a deficient number, since it is larger than the sum of its proper divisors (27481).

28689191 is a wasteful number, since it uses less digits than its factorization.

28689191 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 27480.

The product of its digits is 62208, while the sum is 44.

The square root of 28689191 is about 5356.2291773224. The cubic root of 28689191 is about 306.1301474091.

The spelling of 28689191 in words is "twenty-eight million, six hundred eighty-nine thousand, one hundred ninety-one".