191899067317 has 2 divisors, whose sum is σ = 191899067318. Its totient is φ = 191899067316.

The previous prime is 191899067299. The next prime is 191899067333. The reversal of 191899067317 is 713760998191.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 152501184196 + 39397883121 = 390514^2 + 198489^2 .

It is a cyclic number.

It is not a de Polignac number, because 191899067317 - 2⁷ = 191899067189 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (191899067417) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 95949533658 + 95949533659.

It is an arithmetic number, because the mean of its divisors is an integer number (95949533659).

Almost surely, 2^191899067317 is an apocalyptic number.

It is an amenable number.

191899067317 is a deficient number, since it is larger than the sum of its proper divisors (1).

191899067317 is an equidigital number, since it uses as much as digits as its factorization.

191899067317 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 5143824, while the sum is 61.

The spelling of 191899067317 in words is "one hundred ninety-one billion, eight hundred ninety-nine million, sixty-seven thousand, three hundred seventeen".