218491171864 has 64 divisors (see below), whose sum is σ = 492118156800. Its totient is φ = 88913958144.

The previous prime is 218491171861. The next prime is 218491171919. The reversal of 218491171864 is 468171194812.

218491171864 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 442654 + ... + 795565.

It is an arithmetic number, because the mean of its divisors is an integer number (7689346200).

Almost surely, 2^218491171864 is an apocalyptic number.

It is an amenable number.

218491171864 is an abundant number, since it is smaller than the sum of its proper divisors (273626984936).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

218491171864 is a wasteful number, since it uses less digits than its factorization.

218491171864 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1238392 (or 1238388 counting only the distinct ones).

The product of its digits is 774144, while the sum is 52.

The spelling of 218491171864 in words is "two hundred eighteen billion, four hundred ninety-one million, one hundred seventy-one thousand, eight hundred sixty-four".