18955091871 has 12 divisors (see below), whose sum is σ = 27828423480. Its totient is φ = 12429568080.

The previous prime is 18955091863. The next prime is 18955091891. The reversal of 18955091871 is 17819055981.

It is a happy number.

18955091871 is a `hidden beast` number, since 1 + 8 + 9 + 550 + 9 + 1 + 87 + 1 = 666.

It is not a de Polignac number, because 18955091871 - 2³ = 18955091863 is a prime.

It is a Smith number, since the sum of its digits (54) coincides with the sum of the digits of its prime factors.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18955091861) 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, 17262741 + ... + 17263838.

It is an arithmetic number, because the mean of its divisors is an integer number (2319035290).

Almost surely, 2^18955091871 is an apocalyptic number.

18955091871 is a deficient number, since it is larger than the sum of its proper divisors (8873331609).

18955091871 is a wasteful number, since it uses less digits than its factorization.

18955091871 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 34526646 (or 34526643 counting only the distinct ones).

The product of its (nonzero) digits is 907200, while the sum is 54.

The spelling of 18955091871 in words is "eighteen billion, nine hundred fifty-five million, ninety-one thousand, eight hundred seventy-one".