90665 has 4 divisors (see below), whose sum is σ = 108804. Its totient is φ = 72528.

The previous prime is 90659. The next prime is 90677. The reversal of 90665 is 56609.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 56609 = 7 ⋅8087.

It can be written as a sum of positive squares in 2 ways, for example, as 34969 + 55696 = 187^2 + 236^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-90665 is a prime.

It is a Duffinian number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 90665.

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 3 ways as a sum of consecutive naturals, for example, 9062 + ... + 9071.

It is an arithmetic number, because the mean of its divisors is an integer number (27201).

2⁹⁰⁶⁶⁵ is an apocalyptic number.

It is an amenable number.

90665 is a deficient number, since it is larger than the sum of its proper divisors (18139).

90665 is a wasteful number, since it uses less digits than its factorization.

90665 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 18138.

The product of its (nonzero) digits is 1620, while the sum is 26.

The square root of 90665 is about 301.1062935244. The cubic root of 90665 is about 44.9241520648.

The spelling of 90665 in words is "ninety thousand, six hundred sixty-five".