18665664675840 has 3024 divisors, whose sum is σ = 87719564919168. Its totient is φ = 3767021862912.

The previous prime is 18665664675821. The next prime is 18665664675841. The reversal of 18665664675840 is 4857646656681.

It is a happy number.

18665664675840 is a `hidden beast` number, since 1 + 8 + 6 + 6 + 566 + 4 + 6 + 7 + 58 + 4 + 0 = 666.

It is a tau number, because it is divible by the number of its divisors (3024).

It is a Harshad number since it is a multiple of its sum of digits (72).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18665664675841) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 143 ways as a sum of consecutive naturals, for example, 811550638069 + ... + 811550638091.

It is an arithmetic number, because the mean of its divisors is an integer number (29007792632).

Almost surely, 2^{18665664675840} is an apocalyptic number.

18665664675840 is a gapful number since it is divisible by the number (10) 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 18665664675840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (43859782459584).

18665664675840 is an abundant number, since it is smaller than the sum of its proper divisors (69053900243328).

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

18665664675840 is an frugal number, since it uses more digits than its factorization.

18665664675840 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 110 (or 53 counting only the distinct ones).

The product of its (nonzero) digits is 1393459200, while the sum is 72.

The spelling of 18665664675840 in words is "eighteen trillion, six hundred sixty-five billion, six hundred sixty-four million, six hundred seventy-five thousand, eight hundred forty".