90805 has 16 divisors (see below), whose sum is σ = 129024. Its totient is φ = 60480.

The previous prime is 90803. The next prime is 90821. The reversal of 90805 is 50809.

It is not a de Polignac number, because 90805 - 2¹ = 90803 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 (90803) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 652 + ... + 778.

It is an arithmetic number, because the mean of its divisors is an integer number (8064).

2⁹⁰⁸⁰⁵ is an apocalyptic number.

It is an amenable number.

90805 is a deficient number, since it is larger than the sum of its proper divisors (38219).

90805 is a wasteful number, since it uses less digits than its factorization.

90805 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 156.

The product of its (nonzero) digits is 360, while the sum is 22.

The square root of 90805 is about 301.3386798936. The cubic root of 90805 is about 44.9472633235.

The spelling of 90805 in words is "ninety thousand, eight hundred five".