91891211 has 2 divisors, whose sum is σ = 91891212. Its totient is φ = 91891210.

The previous prime is 91891139. The next prime is 91891213. The reversal of 91891211 is 11219819.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 91891211 - 2²⁶ = 24782347 is a prime.

Together with 91891213, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (91891213) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 45945605 + 45945606.

It is an arithmetic number, because the mean of its divisors is an integer number (45945606).

Almost surely, 2^91891211 is an apocalyptic number.

91891211 is a deficient number, since it is larger than the sum of its proper divisors (1).

91891211 is an equidigital number, since it uses as much as digits as its factorization.

91891211 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1296, while the sum is 32.

The square root of 91891211 is about 9585.9903505063. The cubic root of 91891211 is about 451.2577340776.

It can be divided in two parts, 918 and 91211, that added together give a palindrome (92129).

The spelling of 91891211 in words is "ninety-one million, eight hundred ninety-one thousand, two hundred eleven".