1681818166656 has 256 divisors, whose sum is σ = 5087746944000. Its totient is φ = 546682853376.

The previous prime is 1681818166649. The next prime is 1681818166673. The reversal of 1681818166656 is 6566618181861.

It is a junction number, because it is equal to n+sod(n) for n = 1681818166593 and 1681818166602.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 44974975 + ... + 45012353.

It is an arithmetic number, because the mean of its divisors is an integer number (19874011500).

Almost surely, 2^{1681818166656} is an apocalyptic number.

1681818166656 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 1681818166656, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2543873472000).

1681818166656 is an abundant number, since it is smaller than the sum of its proper divisors (3405928777344).

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

1681818166656 is a wasteful number, since it uses less digits than its factorization.

1681818166656 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 37726 (or 37708 counting only the distinct ones).

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

The spelling of 1681818166656 in words is "one trillion, six hundred eighty-one billion, eight hundred eighteen million, one hundred sixty-six thousand, six hundred fifty-six".