12805440280866 has 64 divisors (see below), whose sum is σ = 28930019788800. Its totient is φ = 4197491020800.

The previous prime is 12805440280849. The next prime is 12805440280891. The reversal of 12805440280866 is 66808204450821.

12805440280866 is a `hidden beast` number, since 1 + 2 + 80 + 5 + 4 + 402 + 80 + 86 + 6 = 666.

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

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 13232386 + ... + 14167106.

It is an arithmetic number, because the mean of its divisors is an integer number (452031559200).

Almost surely, 2^{12805440280866} is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 12805440280866, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (14465009894400).

12805440280866 is an abundant number, since it is smaller than the sum of its proper divisors (16124579507934).

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

12805440280866 is a wasteful number, since it uses less digits than its factorization.

12805440280866 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 938952 (or 938946 counting only the distinct ones).

The product of its (nonzero) digits is 5898240, while the sum is 54.

The spelling of 12805440280866 in words is "twelve trillion, eight hundred five billion, four hundred forty million, two hundred eighty thousand, eight hundred sixty-six".