91688899 has 2 divisors, whose sum is σ = 91688900. Its totient is φ = 91688898.

The previous prime is 91688893. The next prime is 91688921. The reversal of 91688899 is 99888619.

It is a weak prime.

It is an emirp because it is prime and its reverse (99888619) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 91688899 - 2⁵ = 91688867 is a prime.

It is not a weakly prime, because it can be changed into another prime (91688893) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 45844449 + 45844450.

It is an arithmetic number, because the mean of its divisors is an integer number (45844450).

Almost surely, 2^91688899 is an apocalyptic number.

91688899 is a deficient number, since it is larger than the sum of its proper divisors (1).

91688899 is an equidigital number, since it uses as much as digits as its factorization.

91688899 is an evil number, because the sum of its binary digits is even.

The product of its digits is 2239488, while the sum is 58.

The square root of 91688899 is about 9575.4320529154. The cubic root of 91688899 is about 450.9263206760.

The spelling of 91688899 in words is "ninety-one million, six hundred eighty-eight thousand, eight hundred ninety-nine".