18938195191 has 2 divisors, whose sum is σ = 18938195192. Its totient is φ = 18938195190.

The previous prime is 18938195189. The next prime is 18938195201. The reversal of 18938195191 is 19159183981.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 18938195191 - 2¹ = 18938195189 is a prime.

Together with 18938195189, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (18938195141) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9469097595 + 9469097596.

It is an arithmetic number, because the mean of its divisors is an integer number (9469097596).

Almost surely, 2^18938195191 is an apocalyptic number.

18938195191 is a deficient number, since it is larger than the sum of its proper divisors (1).

18938195191 is an equidigital number, since it uses as much as digits as its factorization.

18938195191 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 699840, while the sum is 55.

The spelling of 18938195191 in words is "eighteen billion, nine hundred thirty-eight million, one hundred ninety-five thousand, one hundred ninety-one".