91664999 has 2 divisors, whose sum is σ = 91665000. Its totient is φ = 91664998.

The previous prime is 91664983. The next prime is 91665029. The reversal of 91664999 is 99946619.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 91664999 - 2⁴ = 91664983 is a 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 91664999.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (91664939) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 45832499 + 45832500.

It is an arithmetic number, because the mean of its divisors is an integer number (45832500).

Almost surely, 2^91664999 is an apocalyptic number.

91664999 is a deficient number, since it is larger than the sum of its proper divisors (1).

91664999 is an equidigital number, since it uses as much as digits as its factorization.

91664999 is an evil number, because the sum of its binary digits is even.

The product of its digits is 944784, while the sum is 53.

The square root of 91664999 is about 9574.1839861160. The cubic root of 91664999 is about 450.8871371771.

The spelling of 91664999 in words is "ninety-one million, six hundred sixty-four thousand, nine hundred ninety-nine".