18911138427 has 24 divisors (see below), whose sum is σ = 27546194000. Its totient is φ = 12501552960.

The previous prime is 18911138417. The next prime is 18911138471. The reversal of 18911138427 is 72483111981.

It is a happy number.

18911138427 is a `hidden beast` number, since 1 + 8 + 91 + 1 + 138 + 427 = 666.

It is not a de Polignac number, because 18911138427 - 2⁷ = 18911138299 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (18911138417) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 691677 + ... + 718497.

Almost surely, 2^18911138427 is an apocalyptic number.

18911138427 is a deficient number, since it is larger than the sum of its proper divisors (8635055573).

18911138427 is a wasteful number, since it uses less digits than its factorization.

18911138427 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 27483 (or 27480 counting only the distinct ones).

The product of its digits is 96768, while the sum is 45.

The spelling of 18911138427 in words is "eighteen billion, nine hundred eleven million, one hundred thirty-eight thousand, four hundred twenty-seven".