2081556811 has 4 divisors (see below), whose sum is σ = 2093185800. Its totient is φ = 2069927824.

The previous prime is 2081556803. The next prime is 2081556901. The reversal of 2081556811 is 1186551802.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 1186551802 = 2 ⋅593275901.

It is a cyclic number.

It is not a de Polignac number, because 2081556811 - 2³ = 2081556803 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (2081556611) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 5814226 + ... + 5814583.

It is an arithmetic number, because the mean of its divisors is an integer number (523296450).

Almost surely, 2^2081556811 is an apocalyptic number.

2081556811 is a deficient number, since it is larger than the sum of its proper divisors (11628989).

2081556811 is a wasteful number, since it uses less digits than its factorization.

2081556811 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11628988.

The product of its (nonzero) digits is 19200, while the sum is 37.

The square root of 2081556811 is about 45624.0814811652. The cubic root of 2081556811 is about 1276.8192531989.

The spelling of 2081556811 in words is "two billion, eighty-one million, five hundred fifty-six thousand, eight hundred eleven".