191238189 has 4 divisors (see below), whose sum is σ = 254984256. Its totient is φ = 127492124.

The previous prime is 191238181. The next prime is 191238191. The reversal of 191238189 is 981832191.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 981832191 = 3 ⋅327277397.

It is a cyclic number.

It is not a de Polignac number, because 191238189 - 2³ = 191238181 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 191238189.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (191238181) 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, 31873029 + ... + 31873034.

It is an arithmetic number, because the mean of its divisors is an integer number (63746064).

Almost surely, 2^191238189 is an apocalyptic number.

It is an amenable number.

191238189 is a deficient number, since it is larger than the sum of its proper divisors (63746067).

191238189 is an equidigital number, since it uses as much as digits as its factorization.

191238189 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 63746066.

The product of its digits is 31104, while the sum is 42.

The square root of 191238189 is about 13828.8896517399. The cubic root of 191238189 is about 576.1358156537.

The spelling of 191238189 in words is "one hundred ninety-one million, two hundred thirty-eight thousand, one hundred eighty-nine".