18201919111 has 4 divisors (see below), whose sum is σ = 18789077824. Its totient is φ = 17614760400.

The previous prime is 18201919093. The next prime is 18201919123. The reversal of 18201919111 is 11191910281.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 11191910281 = 80173 ⋅139597.

It is a cyclic number.

It is not a de Polignac number, because 18201919111 - 2⁷ = 18201918983 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18201919181) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 293579310 + ... + 293579371.

It is an arithmetic number, because the mean of its divisors is an integer number (4697269456).

Almost surely, 2^18201919111 is an apocalyptic number.

18201919111 is a deficient number, since it is larger than the sum of its proper divisors (587158713).

18201919111 is an equidigital number, since it uses as much as digits as its factorization.

18201919111 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 587158712.

The product of its (nonzero) digits is 1296, while the sum is 34.

The spelling of 18201919111 in words is "eighteen billion, two hundred one million, nine hundred nineteen thousand, one hundred eleven".