28194855521 has 32 divisors (see below), whose sum is σ = 34918428672. Its totient is φ = 22213981440.

The previous prime is 28194855517. The next prime is 28194855527. The reversal of 28194855521 is 12555849182.

It is a happy number.

It is not a de Polignac number, because 28194855521 - 2² = 28194855517 is a prime.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 28194855521.

It is not an unprimeable number, because it can be changed into a prime (28194855527) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 2741030 + ... + 2751296.

It is an arithmetic number, because the mean of its divisors is an integer number (1091200896).

Almost surely, 2^28194855521 is an apocalyptic number.

It is an amenable number.

28194855521 is a deficient number, since it is larger than the sum of its proper divisors (6723573151).

28194855521 is a wasteful number, since it uses less digits than its factorization.

28194855521 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10829.

The product of its digits is 1152000, while the sum is 50.

The spelling of 28194855521 in words is "twenty-eight billion, one hundred ninety-four million, eight hundred fifty-five thousand, five hundred twenty-one".