231031 has 2 divisors, whose sum is σ = 231032. Its totient is φ = 231030.

The previous prime is 231019. The next prime is 231041. The reversal of 231031 is 130132.

It is an a-pointer prime, because the next prime (231041) can be obtained adding 231031 to its sum of digits (10).

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 231031 - 2⁵ = 230999 is a prime.

It is a super-2 number, since 2×231031² = 106750645922, which contains 22 as substring.

It is an Ulam number.

It is a junction number, because it is equal to n+sod(n) for n = 230999 and 231017.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (231001) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 115515 + 115516.

It is an arithmetic number, because the mean of its divisors is an integer number (115516).

2²³¹⁰³¹ is an apocalyptic number.

231031 is a deficient number, since it is larger than the sum of its proper divisors (1).

231031 is an equidigital number, since it uses as much as digits as its factorization.

231031 is an odious number, because the sum of its binary digits is odd.

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

The square root of 231031 is about 480.6568422482. The cubic root of 231031 is about 61.3606690006.

Adding to 231031 its reverse (130132), we get a palindrome (361163).

It can be divided in two parts, 23103 and 1, that added together give a square (23104 = 152²).

The spelling of 231031 in words is "two hundred thirty-one thousand, thirty-one".