191688361 has 2 divisors, whose sum is σ = 191688362. Its totient is φ = 191688360.

The previous prime is 191688353. The next prime is 191688373. The reversal of 191688361 is 163886191.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 118483225 + 73205136 = 10885^2 + 8556^2 .

It is a cyclic number.

It is not a de Polignac number, because 191688361 - 2³ = 191688353 is a prime.

It is not a weakly prime, because it can be changed into another prime (191688331) 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, 95844180 + 95844181.

It is an arithmetic number, because the mean of its divisors is an integer number (95844181).

Almost surely, 2^191688361 is an apocalyptic number.

It is an amenable number.

191688361 is a deficient number, since it is larger than the sum of its proper divisors (1).

191688361 is an equidigital number, since it uses as much as digits as its factorization.

191688361 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 62208, while the sum is 43.

The square root of 191688361 is about 13845.1565899415. The cubic root of 191688361 is about 576.5875332550.

The spelling of 191688361 in words is "one hundred ninety-one million, six hundred eighty-eight thousand, three hundred sixty-one".