191664064127 has 2 divisors, whose sum is σ = 191664064128. Its totient is φ = 191664064126.

The previous prime is 191664064021. The next prime is 191664064147. The reversal of 191664064127 is 721460466191.

It is a strong prime.

It is an emirp because it is prime and its reverse (721460466191) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 191664064127 - 2²² = 191659869823 is a prime.

It is a super-2 number, since 2×191664064127² (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 (191664064147) 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, 95832032063 + 95832032064.

It is an arithmetic number, because the mean of its divisors is an integer number (95832032064).

Almost surely, 2^191664064127 is an apocalyptic number.

191664064127 is a deficient number, since it is larger than the sum of its proper divisors (1).

191664064127 is an equidigital number, since it uses as much as digits as its factorization.

191664064127 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 435456, while the sum is 47.

The spelling of 191664064127 in words is "one hundred ninety-one billion, six hundred sixty-four million, sixty-four thousand, one hundred twenty-seven".