231688 has 8 divisors (see below), whose sum is σ = 434430. Its totient is φ = 115840.

The previous prime is 231677. The next prime is 231701. The reversal of 231688 is 886132.

231688 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in only one way, i.e., 142884 + 88804 = 378^2 + 298^2 .

It is a tau number, because it is divible by the number of its divisors (8).

It is a hoax number, since the sum of its digits (28) coincides with the sum of the digits of its distinct prime factors.

It is a plaindrome in base 15.

It is an unprimeable number.

231688 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 14473 + ... + 14488.

2²³¹⁶⁸⁸ is an apocalyptic number.

It is an amenable number.

231688 is a deficient number, since it is larger than the sum of its proper divisors (202742).

231688 is a wasteful number, since it uses less digits than its factorization.

231688 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 28967 (or 28963 counting only the distinct ones).

The product of its digits is 2304, while the sum is 28.

The square root of 231688 is about 481.3397968172. The cubic root of 231688 is about 61.4187792473.

It can be divided in two parts, 231 and 688, that added together give a palindrome (919).

The spelling of 231688 in words is "two hundred thirty-one thousand, six hundred eighty-eight".