231312 has 40 divisors (see below), whose sum is σ = 615040. Its totient is φ = 74880.

The previous prime is 231299. The next prime is 231317. The reversal of 231312 is 213132.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (12).

It is a nude number because it is divisible by every one of its digits.

It is not an unprimeable number, because it can be changed into a prime (231317) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2889 + ... + 2967.

It is an arithmetic number, because the mean of its divisors is an integer number (15376).

2²³¹³¹² 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 231312, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (307520).

231312 is an abundant number, since it is smaller than the sum of its proper divisors (383728).

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

231312 is a wasteful number, since it uses less digits than its factorization.

231312 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 151 (or 145 counting only the distinct ones).

The product of its digits is 36, while the sum is 12.

The square root of 231312 is about 480.9490617519. The cubic root of 231312 is about 61.3855363159.

Adding to 231312 its reverse (213132), we get a palindrome (444444).

The spelling of 231312 in words is "two hundred thirty-one thousand, three hundred twelve".