18811811 has 4 divisors (see below), whose sum is σ = 18861312. Its totient is φ = 18762312.

The previous prime is 18811789. The next prime is 18811813. The reversal of 18811811 is 11811881.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 11811881 = 863 ⋅13687.

It is a cyclic number.

It is not a de Polignac number, because 18811811 - 2¹⁸ = 18549667 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (18811813) 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, 24176 + ... + 24941.

It is an arithmetic number, because the mean of its divisors is an integer number (4715328).

Almost surely, 2^18811811 is an apocalyptic number.

18811811 is a deficient number, since it is larger than the sum of its proper divisors (49501).

18811811 is an equidigital number, since it uses as much as digits as its factorization.

18811811 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 49500.

The product of its digits is 512, while the sum is 29.

The square root of 18811811 is about 4337.2584658976. The cubic root of 18811811 is about 265.9562509315.

The spelling of 18811811 in words is "eighteen million, eight hundred eleven thousand, eight hundred eleven".