18731585664 has 640 divisors, whose sum is σ = 65509361280. Its totient is φ = 5255331840.

The previous prime is 18731585657. The next prime is 18731585683. The reversal of 18731585664 is 46658513781.

It is a happy number.

18731585664 is a `hidden beast` number, since 1 + 8 + 73 + 1 + 5 + 8 + 566 + 4 = 666.

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 18731585664.

It is an unprimeable number.

It is a polite number, since it can be written in 79 ways as a sum of consecutive naturals, for example, 97054752 + ... + 97054944.

It is an arithmetic number, because the mean of its divisors is an integer number (102358377).

Almost surely, 2^18731585664 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 18731585664, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (32754680640).

18731585664 is an abundant number, since it is smaller than the sum of its proper divisors (46777775616).

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

18731585664 is a wasteful number, since it uses less digits than its factorization.

18731585664 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 290 (or 269 counting only the distinct ones).

The product of its digits is 4838400, while the sum is 54.

The spelling of 18731585664 in words is "eighteen billion, seven hundred thirty-one million, five hundred eighty-five thousand, six hundred sixty-four".