191508668831 has 2 divisors, whose sum is σ = 191508668832. Its totient is φ = 191508668830.

The previous prime is 191508668759. The next prime is 191508668833. The reversal of 191508668831 is 138866805191.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-191508668831 is a prime.

It is a super-2 number, since 2×191508668831² (a number of 23 digits) contains 22 as substring.

Together with 191508668833, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (191508668833) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 95754334415 + 95754334416.

It is an arithmetic number, because the mean of its divisors is an integer number (95754334416).

Almost surely, 2^191508668831 is an apocalyptic number.

191508668831 is a deficient number, since it is larger than the sum of its proper divisors (1).

191508668831 is an equidigital number, since it uses as much as digits as its factorization.

191508668831 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 2488320, while the sum is 56.

The spelling of 191508668831 in words is "one hundred ninety-one billion, five hundred eight million, six hundred sixty-eight thousand, eight hundred thirty-one".