1816801816806 has 64 divisors (see below), whose sum is σ = 4132621405440. Its totient is φ = 591317496000.

The previous prime is 1816801816783. The next prime is 1816801816811. The reversal of 1816801816806 is 6086181086181.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (54).

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, 6837961 + ... + 7098683.

It is an arithmetic number, because the mean of its divisors is an integer number (64572209460).

Almost surely, 2^{1816801816806} is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1816801816806, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2066310702720).

1816801816806 is an abundant number, since it is smaller than the sum of its proper divisors (2315819588634).

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

1816801816806 is a wasteful number, since it uses less digits than its factorization.

1816801816806 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 263778 (or 263772 counting only the distinct ones).

The product of its (nonzero) digits is 884736, while the sum is 54.

The spelling of 1816801816806 in words is "one trillion, eight hundred sixteen billion, eight hundred one million, eight hundred sixteen thousand, eight hundred six".