18281780917664 has 48 divisors (see below), whose sum is σ = 39325344156000. Its totient is φ = 8296976674560.

The previous prime is 18281780917651. The next prime is 18281780917681. The reversal of 18281780917664 is 46671908718281.

It is a junction number, because it is equal to n+sod(n) for n = 18281780917594 and 18281780917603.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 40160039 + ... + 40612710.

It is an arithmetic number, because the mean of its divisors is an integer number (819278003250).

Almost surely, 2^{18281780917664} is an apocalyptic number.

It is an amenable number.

18281780917664 is an abundant number, since it is smaller than the sum of its proper divisors (21043563238336).

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

18281780917664 is a wasteful number, since it uses less digits than its factorization.

18281780917664 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 80773413 (or 80773405 counting only the distinct ones).

The product of its (nonzero) digits is 65028096, while the sum is 68.

The spelling of 18281780917664 in words is "eighteen trillion, two hundred eighty-one billion, seven hundred eighty million, nine hundred seventeen thousand, six hundred sixty-four".