28678859191 has 4 divisors (see below), whose sum is σ = 29667785400. Its totient is φ = 27689932984.

The previous prime is 28678859161. The next prime is 28678859207. The reversal of 28678859191 is 19195887682.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-28678859191 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 (28678859161) 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, 494463061 + ... + 494463118.

It is an arithmetic number, because the mean of its divisors is an integer number (7416946350).

Almost surely, 2^28678859191 is an apocalyptic number.

28678859191 is a deficient number, since it is larger than the sum of its proper divisors (988926209).

28678859191 is an equidigital number, since it uses as much as digits as its factorization.

28678859191 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 988926208.

The product of its digits is 17418240, while the sum is 64.

The spelling of 28678859191 in words is "twenty-eight billion, six hundred seventy-eight million, eight hundred fifty-nine thousand, one hundred ninety-one".