218638489944 has 64 divisors (see below), whose sum is σ = 624894359040. Its totient is φ = 62446844160.

The previous prime is 218638489873. The next prime is 218638489967. The reversal of 218638489944 is 449984836812.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 275749 + ... + 716459.

It is an arithmetic number, because the mean of its divisors is an integer number (9763974360).

Almost surely, 2^218638489944 is an apocalyptic number.

218638489944 is a gapful number since it is divisible by the number (24) formed by its first and last digit.

It is an amenable number.

218638489944 is an abundant number, since it is smaller than the sum of its proper divisors (406255869096).

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

218638489944 is a wasteful number, since it uses less digits than its factorization.

218638489944 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 443680 (or 443676 counting only the distinct ones).

The product of its digits is 95551488, while the sum is 66.

The spelling of 218638489944 in words is "two hundred eighteen billion, six hundred thirty-eight million, four hundred eighty-nine thousand, nine hundred forty-four".