91691 has 2 divisors, whose sum is σ = 91692. Its totient is φ = 91690.

The previous prime is 91673. The next prime is 91703. The reversal of 91691 is 19619.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 91691 - 2¹⁴ = 75307 is a prime.

It is a Sophie Germain prime.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 91691.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 91691.

It is not a weakly prime, because it can be changed into another prime (91621) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 45845 + 45846.

It is an arithmetic number, because the mean of its divisors is an integer number (45846).

2⁹¹⁶⁹¹ is an apocalyptic number.

91691 is a deficient number, since it is larger than the sum of its proper divisors (1).

91691 is an equidigital number, since it uses as much as digits as its factorization.

91691 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 486, while the sum is 26.

The square root of 91691 is about 302.8052179207. The cubic root of 91691 is about 45.0929764891.

The spelling of 91691 in words is "ninety-one thousand, six hundred ninety-one".