91929191 has 2 divisors, whose sum is σ = 91929192. Its totient is φ = 91929190.

The previous prime is 91929151. The next prime is 91929193. The reversal of 91929191 is 19192919.

It is a happy number.

It is a strong prime.

It is an emirp because it is prime and its reverse (19192919) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 91929191 - 2¹⁰ = 91928167 is a prime.

Together with 91929193, 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 (91929193) 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, 45964595 + 45964596.

It is an arithmetic number, because the mean of its divisors is an integer number (45964596).

Almost surely, 2^91929191 is an apocalyptic number.

91929191 is a deficient number, since it is larger than the sum of its proper divisors (1).

91929191 is an equidigital number, since it uses as much as digits as its factorization.

91929191 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 13122, while the sum is 41.

The square root of 91929191 is about 9587.9711618256. The cubic root of 91929191 is about 451.3198960184.

The spelling of 91929191 in words is "ninety-one million, nine hundred twenty-nine thousand, one hundred ninety-one".