31385 has 4 divisors (see below), whose sum is σ = 37668. Its totient is φ = 25104.

The previous prime is 31379. The next prime is 31387. The reversal of 31385 is 58313.

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 23104 + 8281 = 152^2 + 91^2 .

It is a cyclic number.

It is not a de Polignac number, because 31385 - 2⁶ = 31321 is a prime.

It is an Ulam number.

It is a Duffinian number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 31385.

It is not an unprimeable number, because it can be changed into a prime (31387) 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, 3134 + ... + 3143.

It is an arithmetic number, because the mean of its divisors is an integer number (9417).

2³¹³⁸⁵ is an apocalyptic number.

It is an amenable number.

31385 is a deficient number, since it is larger than the sum of its proper divisors (6283).

31385 is an equidigital number, since it uses as much as digits as its factorization.

31385 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6282.

The product of its digits is 360, while the sum is 20.

The square root of 31385 is about 177.1581214622. The cubic root of 31385 is about 31.5433182472.

Adding to 31385 its reverse (58313), we get a palindrome (89698).

It can be divided in two parts, 31 and 385, that multiplied together give a triangular number (11935 = T₁₅₄).

The spelling of 31385 in words is "thirty-one thousand, three hundred eighty-five".