91959191 has 2 divisors, whose sum is σ = 91959192. Its totient is φ = 91959190.

The previous prime is 91959173. The next prime is 91959193. The reversal of 91959191 is 19195919.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-91959191 is a prime.

Together with 91959193, 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 (91959193) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 45979595 + 45979596.

It is an arithmetic number, because the mean of its divisors is an integer number (45979596).

Almost surely, 2^91959191 is an apocalyptic number.

91959191 is a deficient number, since it is larger than the sum of its proper divisors (1).

91959191 is an equidigital number, since it uses as much as digits as its factorization.

91959191 is an evil number, because the sum of its binary digits is even.

The product of its digits is 32805, while the sum is 44.

The square root of 91959191 is about 9589.5354944856. The cubic root of 91959191 is about 451.3689849754.

The spelling of 91959191 in words is "ninety-one million, nine hundred fifty-nine thousand, one hundred ninety-one".