218491171868 has 6 divisors (see below), whose sum is σ = 382359550776. Its totient is φ = 109245585932.

The previous prime is 218491171861. The next prime is 218491171919. The reversal of 218491171868 is 868171194812.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (218491171861) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 27311396480 + ... + 27311396487.

It is an arithmetic number, because the mean of its divisors is an integer number (63726591796).

Almost surely, 2^218491171868 is an apocalyptic number.

It is an amenable number.

218491171868 is a deficient number, since it is larger than the sum of its proper divisors (163868378908).

218491171868 is a wasteful number, since it uses less digits than its factorization.

218491171868 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 54622792971 (or 54622792969 counting only the distinct ones).

The product of its digits is 1548288, while the sum is 56.

The spelling of 218491171868 in words is "two hundred eighteen billion, four hundred ninety-one million, one hundred seventy-one thousand, eight hundred sixty-eight".