91131091 has 2 divisors, whose sum is σ = 91131092. Its totient is φ = 91131090.

The previous prime is 91131059. The next prime is 91131097. The reversal of 91131091 is 19013119.

It is a strong prime.

It is an emirp because it is prime and its reverse (19013119) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 91131091 - 2⁵ = 91131059 is a prime.

It is not a weakly prime, because it can be changed into another prime (91131097) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 45565545 + 45565546.

It is an arithmetic number, because the mean of its divisors is an integer number (45565546).

Almost surely, 2^91131091 is an apocalyptic number.

91131091 is a deficient number, since it is larger than the sum of its proper divisors (1).

91131091 is an equidigital number, since it uses as much as digits as its factorization.

91131091 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 243, while the sum is 25.

The square root of 91131091 is about 9546.2605767913. The cubic root of 91131091 is about 450.0100261141.

The spelling of 91131091 in words is "ninety-one million, one hundred thirty-one thousand, ninety-one".