18155125881 has 12 divisors (see below), whose sum is σ = 26233673700. Its totient is φ = 12098985120.

The previous prime is 18155125853. The next prime is 18155125883. The reversal of 18155125881 is 18852155181.

18155125881 is a `hidden beast` number, since 1 + 8 + 1 + 5 + 512 + 58 + 81 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 1653154281 + 16501971600 = 40659^2 + 128460^2 .

It is a de Polignac number, because none of the positive numbers 2^k-18155125881 is a prime.

It is a super-2 number, since 2×18155125881² (a number of 21 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (18155125883) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 343306 + ... + 392643.

It is an arithmetic number, because the mean of its divisors is an integer number (2186139475).

Almost surely, 2^18155125881 is an apocalyptic number.

It is an amenable number.

18155125881 is a deficient number, since it is larger than the sum of its proper divisors (8078547819).

18155125881 is a wasteful number, since it uses less digits than its factorization.

18155125881 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 738696 (or 738693 counting only the distinct ones).

The product of its digits is 128000, while the sum is 45.

The spelling of 18155125881 in words is "eighteen billion, one hundred fifty-five million, one hundred twenty-five thousand, eight hundred eighty-one".