91205 has 16 divisors (see below), whose sum is σ = 123120. Its totient is φ = 64512.

The previous prime is 91199. The next prime is 91229. The reversal of 91205 is 50219.

It is a Cunningham number, because it is equal to 302²+1.

It can be written as a sum of positive squares in 8 ways, for example, as 8836 + 82369 = 94^2 + 287^2 .

It is a cyclic number.

It is not a de Polignac number, because 91205 - 2⁶ = 91141 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (17).

It is a zygodrome in base 3.

It is a congruent 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 15 ways as a sum of consecutive naturals, for example, 2447 + ... + 2483.

It is an arithmetic number, because the mean of its divisors is an integer number (7695).

2⁹¹²⁰⁵ is an apocalyptic number.

It is an amenable number.

91205 is a deficient number, since it is larger than the sum of its proper divisors (31915).

91205 is a wasteful number, since it uses less digits than its factorization.

91205 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 88.

The product of its (nonzero) digits is 90, while the sum is 17.

The square root of 91205 is about 302.0016556246. The cubic root of 91205 is about 45.0131648725.

The spelling of 91205 in words is "ninety-one thousand, two hundred five".