91665 has 32 divisors (see below), whose sum is σ = 188160. Its totient is φ = 41472.

The previous prime is 91639. The next prime is 91673. The reversal of 91665 is 56619.

It is not a de Polignac number, because 91665 - 2⁹ = 91153 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (27).

91665 is a lucky number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 897 + ... + 993.

It is an arithmetic number, because the mean of its divisors is an integer number (5880).

2⁹¹⁶⁶⁵ is an apocalyptic number.

It is an amenable number.

91665 is an abundant number, since it is smaller than the sum of its proper divisors (96495).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

It is a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (94080).

91665 is a wasteful number, since it uses less digits than its factorization.

91665 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 118 (or 112 counting only the distinct ones).

The product of its digits is 1620, while the sum is 27.

The square root of 91665 is about 302.7622829878. The cubic root of 91665 is about 45.0887138817.

The spelling of 91665 in words is "ninety-one thousand, six hundred sixty-five".