91955191 has 2 divisors, whose sum is σ = 91955192. Its totient is φ = 91955190.

The previous prime is 91955161. The next prime is 91955197. The reversal of 91955191 is 19155919.

It is a strong prime.

It is an emirp because it is prime and its reverse (19155919) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 91955191 - 2⁷ = 91955063 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (91955197) by changing a digit.

It is an upside-down number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 45977595 + 45977596.

It is an arithmetic number, because the mean of its divisors is an integer number (45977596).

Almost surely, 2^91955191 is an apocalyptic number.

91955191 is a deficient number, since it is larger than the sum of its proper divisors (1).

91955191 is an equidigital number, since it uses as much as digits as its factorization.

91955191 is an evil number, because the sum of its binary digits is even.

The product of its digits is 18225, while the sum is 40.

The square root of 91955191 is about 9589.3269315422. The cubic root of 91955191 is about 451.3624403980.

The spelling of 91955191 in words is "ninety-one million, nine hundred fifty-five thousand, one hundred ninety-one".