218372744664 has 128 divisors (see below), whose sum is σ = 638181028800. Its totient is φ = 69096084480.

The previous prime is 218372744651. The next prime is 218372744693. The reversal of 218372744664 is 466447273812.

It is a super-2 number, since 2×218372744664² (a number of 23 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (54).

It is a self number, because there is not a number n which added to its sum of digits gives 218372744664.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 5547 + ... + 660890.

Almost surely, 2^218372744664 is an apocalyptic number.

218372744664 is a gapful number since it is divisible by the number (24) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 218372744664, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (319090514400).

218372744664 is an abundant number, since it is smaller than the sum of its proper divisors (419808284136).

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

218372744664 is a wasteful number, since it uses less digits than its factorization.

218372744664 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 666530 (or 666520 counting only the distinct ones).

The product of its digits is 10838016, while the sum is 54.

The spelling of 218372744664 in words is "two hundred eighteen billion, three hundred seventy-two million, seven hundred forty-four thousand, six hundred sixty-four".