31312 has 20 divisors (see below), whose sum is σ = 64480. Its totient is φ = 14688.

The previous prime is 31307. The next prime is 31319. The reversal of 31312 is 21313.

It is a plaindrome in base 13.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31319) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 253 + ... + 355.

It is an arithmetic number, because the mean of its divisors is an integer number (3224).

2³¹³¹² is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 31312, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (32240).

31312 is an abundant number, since it is smaller than the sum of its proper divisors (33168).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

31312 is a wasteful number, since it uses less digits than its factorization.

31312 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 130 (or 124 counting only the distinct ones).

The product of its digits is 18, while the sum is 10.

The square root of 31312 is about 176.9519708848. The cubic root of 31312 is about 31.5188431812.

Adding to 31312 its reverse (21313), we get a palindrome (52625).

Subtracting from 31312 its reverse (21313), we obtain a palindrome (9999).

It can be divided in two parts, 313 and 12, that added together give a triangular number (325 = T₂₅).

The spelling of 31312 in words is "thirty-one thousand, three hundred twelve".