31085 has 4 divisors (see below), whose sum is σ = 37308. Its totient is φ = 24864.

The previous prime is 31081. The next prime is 31091. The reversal of 31085 is 58013.

31085 = T₁₀₉ + T₁₁₀ + ... + T₁₁₃.

31085 is nontrivially palindromic in base 4.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 17161 + 13924 = 131^2 + 118^2 .

It is a cyclic number.

It is not a de Polignac number, because 31085 - 2² = 31081 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 31085.

It is not an unprimeable number, because it can be changed into a prime (31081) 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, 3104 + ... + 3113.

It is an arithmetic number, because the mean of its divisors is an integer number (9327).

2³¹⁰⁸⁵ is an apocalyptic number.

It is an amenable number.

31085 is a deficient number, since it is larger than the sum of its proper divisors (6223).

31085 is an equidigital number, since it uses as much as digits as its factorization.

31085 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6222.

The product of its (nonzero) digits is 120, while the sum is 17.

The square root of 31085 is about 176.3093871579. The cubic root of 31085 is about 31.4424918657.

Adding to 31085 its reverse (58013), we get a palindrome (89098).

It can be divided in two parts, 3108 and 5, that added together give a palindrome (3113).

The spelling of 31085 in words is "thirty-one thousand, eighty-five".