189881191 has 2 divisors, whose sum is σ = 189881192. Its totient is φ = 189881190.

The previous prime is 189881189. The next prime is 189881207. The reversal of 189881191 is 191188981.

It is a weak prime.

It is an emirp because it is prime and its reverse (191188981) is a distict prime. It is also a bemirp because it and its reverse can be mirrored producing other two distinct primes, 161188681 and 186881161.

It is a cyclic number.

It is not a de Polignac number, because 189881191 - 2¹ = 189881189 is a prime.

Together with 189881189, 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 (189881101) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 94940595 + 94940596.

It is an arithmetic number, because the mean of its divisors is an integer number (94940596).

Almost surely, 2^189881191 is an apocalyptic number.

189881191 is a deficient number, since it is larger than the sum of its proper divisors (1).

189881191 is an equidigital number, since it uses as much as digits as its factorization.

189881191 is an evil number, because the sum of its binary digits is even.

The product of its digits is 41472, while the sum is 46.

The square root of 189881191 is about 13779.7384227713. The cubic root of 189881191 is about 574.7698547139.

The spelling of 189881191 in words is "one hundred eighty-nine million, eight hundred eighty-one thousand, one hundred ninety-one".