231231031 has 2 divisors, whose sum is σ = 231231032. Its totient is φ = 231231030.

The previous prime is 231231017. The next prime is 231231037. The reversal of 231231031 is 130132132.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 231231031 - 2¹³ = 231222839 is a prime.

It is a super-2 number, since 2×231231031² = 106935579394645922, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 231230996 and 231231014.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (231231037) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 115615515 + 115615516.

It is an arithmetic number, because the mean of its divisors is an integer number (115615516).

Almost surely, 2^231231031 is an apocalyptic number.

231231031 is a deficient number, since it is larger than the sum of its proper divisors (1).

231231031 is an equidigital number, since it uses as much as digits as its factorization.

231231031 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 108, while the sum is 16.

The square root of 231231031 is about 15206.2826160768. The cubic root of 231231031 is about 613.7837296722.

Adding to 231231031 its reverse (130132132), we get a palindrome (361363163).

The spelling of 231231031 in words is "two hundred thirty-one million, two hundred thirty-one thousand, thirty-one".