18911894131 has 48 divisors (see below), whose sum is σ = 22359613440. Its totient is φ = 15927425280.

The previous prime is 18911894119. The next prime is 18911894179. The reversal of 18911894131 is 13149811981.

It is a happy number.

It is not a de Polignac number, because 18911894131 - 2¹³ = 18911885939 is a prime.

It is a super-2 number, since 2×18911894131² (a number of 21 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (18911894191) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 31156030 + ... + 31156636.

It is an arithmetic number, because the mean of its divisors is an integer number (465825280).

Almost surely, 2^18911894131 is an apocalyptic number.

18911894131 is a deficient number, since it is larger than the sum of its proper divisors (3447719309).

18911894131 is a wasteful number, since it uses less digits than its factorization.

18911894131 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 996 (or 983 counting only the distinct ones).

The product of its digits is 62208, while the sum is 46.

The spelling of 18911894131 in words is "eighteen billion, nine hundred eleven million, eight hundred ninety-four thousand, one hundred thirty-one".