91065599 has 4 divisors (see below), whose sum is σ = 91150464. Its totient is φ = 90980736.

The previous prime is 91065593. The next prime is 91065641. The reversal of 91065599 is 99556019.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 91065599 - 2⁸ = 91065343 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (91065593) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 40802 + ... + 42975.

It is an arithmetic number, because the mean of its divisors is an integer number (22787616).

Almost surely, 2^91065599 is an apocalyptic number.

91065599 is a deficient number, since it is larger than the sum of its proper divisors (84865).

91065599 is a wasteful number, since it uses less digits than its factorization.

91065599 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 84864.

The product of its (nonzero) digits is 109350, while the sum is 44.

The square root of 91065599 is about 9542.8297165987. The cubic root of 91065599 is about 449.9021993222.

The spelling of 91065599 in words is "ninety-one million, sixty-five thousand, five hundred ninety-nine".