91842809 has 2 divisors, whose sum is σ = 91842810. Its totient is φ = 91842808.

The previous prime is 91842781. The next prime is 91842889. The reversal of 91842809 is 90824819.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 80640400 + 11202409 = 8980^2 + 3347^2 .

It is an emirp because it is prime and its reverse (90824819) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 91842809 - 2²⁰ = 90794233 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (91842889) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 45921404 + 45921405.

It is an arithmetic number, because the mean of its divisors is an integer number (45921405).

Almost surely, 2^91842809 is an apocalyptic number.

It is an amenable number.

91842809 is a deficient number, since it is larger than the sum of its proper divisors (1).

91842809 is an equidigital number, since it uses as much as digits as its factorization.

91842809 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 41472, while the sum is 41.

The square root of 91842809 is about 9583.4653961915. The cubic root of 91842809 is about 451.1784896005.

The spelling of 91842809 in words is "ninety-one million, eight hundred forty-two thousand, eight hundred nine".