191239019 has 2 divisors, whose sum is σ = 191239020. Its totient is φ = 191239018.

The previous prime is 191238959. The next prime is 191239033. The reversal of 191239019 is 910932191.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-191239019 is a prime.

It is a super-2 number, since 2×191239019² = 73144724776164722, which contains 22 as substring.

It is a Sophie Germain prime.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 191239019.

It is not a weakly prime, because it can be changed into another prime (191230019) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 95619509 + 95619510.

It is an arithmetic number, because the mean of its divisors is an integer number (95619510).

Almost surely, 2^191239019 is an apocalyptic number.

191239019 is a deficient number, since it is larger than the sum of its proper divisors (1).

191239019 is an equidigital number, since it uses as much as digits as its factorization.

191239019 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 4374, while the sum is 35.

The square root of 191239019 is about 13828.9196613474. The cubic root of 191239019 is about 576.1366491554.

The spelling of 191239019 in words is "one hundred ninety-one million, two hundred thirty-nine thousand, nineteen".