2805863888891 has 16 divisors (see below), whose sum is σ = 3242278803456. Its totient is φ = 2378489489376.

The previous prime is 2805863888827. The next prime is 2805863888981. The reversal of 2805863888891 is 1988883685082.

It is not a de Polignac number, because 2805863888891 - 2⁶ = 2805863888827 is a prime.

It is not an unprimeable number, because it can be changed into a prime (2805863888591) by changing a digit.

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 15 ways as a sum of consecutive naturals, for example, 5861651 + ... + 6322236.

It is an arithmetic number, because the mean of its divisors is an integer number (202642425216).

Almost surely, 2^{2805863888891} is an apocalyptic number.

2805863888891 is a deficient number, since it is larger than the sum of its proper divisors (436414914565).

2805863888891 is a wasteful number, since it uses less digits than its factorization.

2805863888891 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12184258.

The product of its (nonzero) digits is 424673280, while the sum is 74.

The spelling of 2805863888891 in words is "two trillion, eight hundred five billion, eight hundred sixty-three million, eight hundred eighty-eight thousand, eight hundred ninety-one".