91906181 has 2 divisors, whose sum is σ = 91906182. Its totient is φ = 91906180.

The previous prime is 91906169. The next prime is 91906193. The reversal of 91906181 is 18160919.

It is a balanced prime because it is at equal distance from previous prime (91906169) and next prime (91906193).

It can be written as a sum of positive squares in only one way, i.e., 85192900 + 6713281 = 9230^2 + 2591^2 .

It is a cyclic number.

It is not a de Polignac number, because 91906181 - 2¹⁰ = 91905157 is a prime.

It is a super-2 number, since 2×91906181² = 16893492212009522, which contains 22 as substring.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (91906141) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 45953090 + 45953091.

It is an arithmetic number, because the mean of its divisors is an integer number (45953091).

Almost surely, 2^91906181 is an apocalyptic number.

It is an amenable number.

91906181 is a deficient number, since it is larger than the sum of its proper divisors (1).

91906181 is an equidigital number, since it uses as much as digits as its factorization.

91906181 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 3888, while the sum is 35.

The square root of 91906181 is about 9586.7711456986. The cubic root of 91906181 is about 451.2822375508.

The spelling of 91906181 in words is "ninety-one million, nine hundred six thousand, one hundred eighty-one".