28158805191789 has 40 divisors (see below), whose sum is σ = 43091842829112. Its totient is φ = 18314034992640.

The previous prime is 28158805191761. The next prime is 28158805191821. The reversal of 28158805191789 is 98719150885182.

28158805191789 is a `hidden beast` number, since 2 + 8 + 15 + 8 + 8 + 0 + 519 + 17 + 89 = 666.

It can be written as a sum of positive squares in 4 ways, for example, as 3313146242025 + 24845658949764 = 1820205^2 + 4984542^2 .

It is not a de Polignac number, because 28158805191789 - 2¹¹ = 28158805189741 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28158805191589) by changing a digit.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 107512777 + ... + 107774369.

Almost surely, 2^{28158805191789} is an apocalyptic number.

It is an amenable number.

28158805191789 is a deficient number, since it is larger than the sum of its proper divisors (14933037637323).

28158805191789 is a wasteful number, since it uses less digits than its factorization.

28158805191789 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 294059 (or 294050 counting only the distinct ones).

The product of its (nonzero) digits is 116121600, while the sum is 72.

The spelling of 28158805191789 in words is "twenty-eight trillion, one hundred fifty-eight billion, eight hundred five million, one hundred ninety-one thousand, seven hundred eighty-nine".