91285 has 4 divisors (see below), whose sum is σ = 109548. Its totient is φ = 73024.

The previous prime is 91283. The next prime is 91291. The reversal of 91285 is 58219.

91285 = 91² + 92² + ... + 100².

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 58219 = 7 ⋅8317.

It can be written as a sum of positive squares in 2 ways, for example, as 30276 + 61009 = 174^2 + 247^2 .

It is a cyclic number.

It is not a de Polignac number, because 91285 - 2¹ = 91283 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 (91283) 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, 9124 + ... + 9133.

It is an arithmetic number, because the mean of its divisors is an integer number (27387).

2⁹¹²⁸⁵ is an apocalyptic number.

It is an amenable number.

91285 is a deficient number, since it is larger than the sum of its proper divisors (18263).

91285 is a wasteful number, since it uses less digits than its factorization.

91285 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18262.

The product of its digits is 720, while the sum is 25.

The square root of 91285 is about 302.1340761980. The cubic root of 91285 is about 45.0263220489.

The spelling of 91285 in words is "ninety-one thousand, two hundred eighty-five".