231831 has 6 divisors (see below), whose sum is σ = 334880. Its totient is φ = 154548.

The previous prime is 231827. The next prime is 231839. The reversal of 231831 is 138132.

It is not a de Polignac number, because 231831 - 2² = 231827 is a prime.

It is a super-2 number, since 2×231831² = 107491225122, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (231839) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 12871 + ... + 12888.

2²³¹⁸³¹ is an apocalyptic number.

231831 is a deficient number, since it is larger than the sum of its proper divisors (103049).

231831 is a wasteful number, since it uses less digits than its factorization.

231831 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 25765 (or 25762 counting only the distinct ones).

The product of its digits is 144, while the sum is 18.

The square root of 231831 is about 481.4883176153. The cubic root of 231831 is about 61.4314127301.

Adding to 231831 its reverse (138132), we get a palindrome (369963).

The spelling of 231831 in words is "two hundred thirty-one thousand, eight hundred thirty-one".