18686625776808 has 256 divisors, whose sum is σ = 56001733171200. Its totient is φ = 5129185628160.

The previous prime is 18686625776747. The next prime is 18686625776821. The reversal of 18686625776808 is 80867752668681.

It is a Cunningham number, because it is equal to 4322803²-1.

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 285272316 + ... + 285337812.

It is an arithmetic number, because the mean of its divisors is an integer number (218756770200).

Almost surely, 2^{18686625776808} 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 18686625776808, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (28000866585600).

18686625776808 is an abundant number, since it is smaller than the sum of its proper divisors (37315107394392).

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

18686625776808 is a wasteful number, since it uses less digits than its factorization.

18686625776808 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 68032 (or 68028 counting only the distinct ones).

The product of its (nonzero) digits is 2601123840, while the sum is 78.

The spelling of 18686625776808 in words is "eighteen trillion, six hundred eighty-six billion, six hundred twenty-five million, seven hundred seventy-six thousand, eight hundred eight".