18181816516656 has 480 divisors, whose sum is σ = 57204752550400. Its totient is φ = 5557365614592.

The previous prime is 18181816516651. The next prime is 18181816516709. The reversal of 18181816516656 is 65661561818181.

It is a happy number.

It is a junction number, because it is equal to n+sod(n) for n = 18181816516593 and 18181816516602.

It is not an unprimeable number, because it can be changed into a prime (18181816516651) by changing a digit.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 9122837196 + ... + 9122839188.

Almost surely, 2^{18181816516656} is an apocalyptic number.

18181816516656 is a gapful number since it is divisible by the number (16) 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 18181816516656, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (28602376275200).

18181816516656 is an abundant number, since it is smaller than the sum of its proper divisors (39022936033744).

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

18181816516656 is a wasteful number, since it uses less digits than its factorization.

18181816516656 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3135 (or 3117 counting only the distinct ones).

The product of its digits is 16588800, while the sum is 63.

The spelling of 18181816516656 in words is "eighteen trillion, one hundred eighty-one billion, eight hundred sixteen million, five hundred sixteen thousand, six hundred fifty-six".