28191829091 has 8 divisors (see below), whose sum is σ = 28280169984. Its totient is φ = 28103551560.

The previous prime is 28191829087. The next prime is 28191829093. The reversal of 28191829091 is 19092819182.

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 28191829091 - 2² = 28191829087 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (28191829093) 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, 970346 + ... + 998976.

It is an arithmetic number, because the mean of its divisors is an integer number (3535021248).

Almost surely, 2^28191829091 is an apocalyptic number.

28191829091 is a deficient number, since it is larger than the sum of its proper divisors (88340893).

28191829091 is a wasteful number, since it uses less digits than its factorization.

28191829091 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 31681.

The product of its (nonzero) digits is 186624, while the sum is 50.

Subtracting from 28191829091 its reverse (19092819182), we obtain a palindrome (9099009909).

The spelling of 28191829091 in words is "twenty-eight billion, one hundred ninety-one million, eight hundred twenty-nine thousand, ninety-one".