18651918060864 has 336 divisors, whose sum is σ = 63112359098880. Its totient is φ = 5406351920640.

The previous prime is 18651918060833. The next prime is 18651918060871. The reversal of 18651918060864 is 46806081915681.

18651918060864 is a `hidden beast` number, since 1 + 8 + 6 + 5 + 1 + 9 + 18 + 0 + 608 + 6 + 4 = 666.

It is a Smith number, since the sum of its digits (63) coincides with the sum of the digits of its prime factors.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 1564447 + ... + 6304865.

It is an arithmetic number, because the mean of its divisors is an integer number (187834402080).

Almost surely, 2^{18651918060864} 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 18651918060864, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (31556179549440).

18651918060864 is an abundant number, since it is smaller than the sum of its proper divisors (44460441038016).

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

18651918060864 is a wasteful number, since it uses less digits than its factorization.

18651918060864 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4740480 (or 4740458 counting only the distinct ones).

The product of its (nonzero) digits is 19906560, while the sum is 63.

The spelling of 18651918060864 in words is "eighteen trillion, six hundred fifty-one billion, nine hundred eighteen million, sixty thousand, eight hundred sixty-four".