18356861664 has 288 divisors, whose sum is σ = 56467756800. Its totient is φ = 5636100096.

The previous prime is 18356861651. The next prime is 18356861741. The reversal of 18356861664 is 46616865381.

18356861664 is a `hidden beast` number, since 1 + 8 + 3 + 568 + 6 + 16 + 64 = 666.

It is a tau number, because it is divible by the number of its divisors (288).

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

It is a self number, because there is not a number n which added to its sum of digits gives 18356861664.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 80867119 + ... + 80867345.

It is an arithmetic number, because the mean of its divisors is an integer number (196068600).

Almost surely, 2^18356861664 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 18356861664, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (28233878400).

18356861664 is an abundant number, since it is smaller than the sum of its proper divisors (38110895136).

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

18356861664 is a wasteful number, since it uses less digits than its factorization.

18356861664 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 542 (or 531 counting only the distinct ones).

The product of its digits is 4976640, while the sum is 54.

The spelling of 18356861664 in words is "eighteen billion, three hundred fifty-six million, eight hundred sixty-one thousand, six hundred sixty-four".