231285 has 16 divisors (see below), whose sum is σ = 392256. Its totient is φ = 115968.

The previous prime is 231277. The next prime is 231289. The reversal of 231285 is 582132.

It is not a de Polignac number, because 231285 - 2³ = 231277 is a prime.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (231289) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 199 + ... + 708.

It is an arithmetic number, because the mean of its divisors is an integer number (24516).

2²³¹²⁸⁵ is an apocalyptic number.

It is an amenable number.

231285 is a deficient number, since it is larger than the sum of its proper divisors (160971).

231285 is a wasteful number, since it uses less digits than its factorization.

With its predecessor (231284) it forms a Ruth-Aaron pair, since the sum of their distinct prime factors is the same (932).

231285 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 932.

The product of its digits is 480, while the sum is 21.

The square root of 231285 is about 480.9209914321. The cubic root of 231285 is about 61.3831478046.

The spelling of 231285 in words is "two hundred thirty-one thousand, two hundred eighty-five".