191397497 has 2 divisors, whose sum is σ = 191397498. Its totient is φ = 191397496.

The previous prime is 191397457. The next prime is 191397511. The reversal of 191397497 is 794793191.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 188760121 + 2637376 = 13739^2 + 1624^2 .

It is an emirp because it is prime and its reverse (794793191) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 191397497 - 2¹⁰ = 191396473 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (191397457) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 95698748 + 95698749.

It is an arithmetic number, because the mean of its divisors is an integer number (95698749).

Almost surely, 2^191397497 is an apocalyptic number.

It is an amenable number.

191397497 is a deficient number, since it is larger than the sum of its proper divisors (1).

191397497 is an equidigital number, since it uses as much as digits as its factorization.

191397497 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 428652, while the sum is 50.

The square root of 191397497 is about 13834.6484234331. The cubic root of 191397497 is about 576.2957515791.

The spelling of 191397497 in words is "one hundred ninety-one million, three hundred ninety-seven thousand, four hundred ninety-seven".