31689 has 12 divisors (see below), whose sum is σ = 52416. Its totient is φ = 18072.

The previous prime is 31687. The next prime is 31699. The reversal of 31689 is 98613.

It is not a de Polignac number, because 31689 - 2¹ = 31687 is a prime.

It is a plaindrome in base 13.

It is not an unprimeable number, because it can be changed into a prime (31687) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 189 + ... + 314.

It is an arithmetic number, because the mean of its divisors is an integer number (4368).

2³¹⁶⁸⁹ is an apocalyptic number.

It is an amenable number.

31689 is a deficient number, since it is larger than the sum of its proper divisors (20727).

31689 is a wasteful number, since it uses less digits than its factorization.

31689 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 516 (or 513 counting only the distinct ones).

The product of its digits is 1296, while the sum is 27.

The square root of 31689 is about 178.0140443898. The cubic root of 31689 is about 31.6448356765.

The spelling of 31689 in words is "thirty-one thousand, six hundred eighty-nine".