2181788811 has 8 divisors (see below), whose sum is σ = 3232279760. Its totient is φ = 1454525856.

The previous prime is 2181788771. The next prime is 2181788821. The reversal of 2181788811 is 1188871812.

It is a happy number.

It is not a de Polignac number, because 2181788811 - 2⁶ = 2181788747 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (2181788821) 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 7 ways as a sum of consecutive naturals, for example, 40403470 + ... + 40403523.

It is an arithmetic number, because the mean of its divisors is an integer number (404034970).

Almost surely, 2^2181788811 is an apocalyptic number.

2181788811 is a deficient number, since it is larger than the sum of its proper divisors (1050490949).

2181788811 is an equidigital number, since it uses as much as digits as its factorization.

2181788811 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 80807002 (or 80806996 counting only the distinct ones).

The product of its digits is 57344, while the sum is 45.

The square root of 2181788811 is about 46709.6222528078. The cubic root of 2181788811 is about 1296.9928145669.

The spelling of 2181788811 in words is "two billion, one hundred eighty-one million, seven hundred eighty-eight thousand, eight hundred eleven".