18201819110191 has 4 divisors (see below), whose sum is σ = 18256809500584. Its totient is φ = 18146828719800.

The previous prime is 18201819110183. The next prime is 18201819110257. The reversal of 18201819110191 is 19101191810281.

It is a happy number.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 18201819110191 - 2³ = 18201819110183 is a prime.

It is a super-2 number, since 2×18201819110191² (a number of 27 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18201819110491) 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, 27495194700 + ... + 27495195361.

It is an arithmetic number, because the mean of its divisors is an integer number (4564202375146).

Almost surely, 2^{18201819110191} is an apocalyptic number.

18201819110191 is a deficient number, since it is larger than the sum of its proper divisors (54990390393).

18201819110191 is an equidigital number, since it uses as much as digits as its factorization.

18201819110191 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 54990390392.

The product of its (nonzero) digits is 10368, while the sum is 43.

The spelling of 18201819110191 in words is "eighteen trillion, two hundred one billion, eight hundred nineteen million, one hundred ten thousand, one hundred ninety-one".