31285 has 4 divisors (see below), whose sum is σ = 37548. Its totient is φ = 25024.

The previous prime is 31277. The next prime is 31307. The reversal of 31285 is 58213.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 58213 = 23 ⋅2531.

It can be written as a sum of positive squares in 2 ways, for example, as 23716 + 7569 = 154^2 + 87^2 .

It is a cyclic number.

It is not a de Polignac number, because 31285 - 2³ = 31277 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3124 + ... + 3133.

It is an arithmetic number, because the mean of its divisors is an integer number (9387).

2³¹²⁸⁵ is an apocalyptic number.

It is an amenable number.

31285 is a deficient number, since it is larger than the sum of its proper divisors (6263).

31285 is an equidigital number, since it uses as much as digits as its factorization.

31285 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6262.

The product of its digits is 240, while the sum is 19.

The square root of 31285 is about 176.8756625429. The cubic root of 31285 is about 31.5097811231.

Adding to 31285 its reverse (58213), we get a palindrome (89498).

The spelling of 31285 in words is "thirty-one thousand, two hundred eighty-five".