191091671 has 2 divisors, whose sum is σ = 191091672. Its totient is φ = 191091670.

The previous prime is 191091653. The next prime is 191091673. The reversal of 191091671 is 176190191.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-191091671 is a prime.

Together with 191091673, 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 (191091673) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 95545835 + 95545836.

It is an arithmetic number, because the mean of its divisors is an integer number (95545836).

Almost surely, 2^191091671 is an apocalyptic number.

191091671 is a deficient number, since it is larger than the sum of its proper divisors (1).

191091671 is an equidigital number, since it uses as much as digits as its factorization.

191091671 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 3402, while the sum is 35.

The square root of 191091671 is about 13823.5911036170. The cubic root of 191091671 is about 575.9886417111.

The spelling of 191091671 in words is "one hundred ninety-one million, ninety-one thousand, six hundred seventy-one".