191749719919 has 2 divisors, whose sum is σ = 191749719920. Its totient is φ = 191749719918.

The previous prime is 191749719911. The next prime is 191749719943. The reversal of 191749719919 is 919917947191.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 191749719919 - 2³ = 191749719911 is a prime.

It is a super-2 number, since 2×191749719919² (a number of 23 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (191749719911) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 95874859959 + 95874859960.

It is an arithmetic number, because the mean of its divisors is an integer number (95874859960).

Almost surely, 2^191749719919 is an apocalyptic number.

191749719919 is a deficient number, since it is larger than the sum of its proper divisors (1).

191749719919 is an equidigital number, since it uses as much as digits as its factorization.

191749719919 is an evil number, because the sum of its binary digits is even.

The product of its digits is 11573604, while the sum is 67.

The spelling of 191749719919 in words is "one hundred ninety-one billion, seven hundred forty-nine million, seven hundred nineteen thousand, nine hundred nineteen".