231312331 has 2 divisors, whose sum is σ = 231312332. Its totient is φ = 231312330.

The previous prime is 231312329. The next prime is 231312349. The reversal of 231312331 is 133213132.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 231312331 - 2¹ = 231312329 is a prime.

It is a super-2 number, since 2×231312331² = 107010788945307122, which contains 22 as substring.

Together with 231312329, it forms a pair of twin primes.

It is a junction number, because it is equal to n+sod(n) for n = 231312299 and 231312308.

It is not a weakly prime, because it can be changed into another prime (231312371) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 115656165 + 115656166.

It is an arithmetic number, because the mean of its divisors is an integer number (115656166).

Almost surely, 2^231312331 is an apocalyptic number.

231312331 is a deficient number, since it is larger than the sum of its proper divisors (1).

231312331 is an equidigital number, since it uses as much as digits as its factorization.

231312331 is an evil number, because the sum of its binary digits is even.

The product of its digits is 324, while the sum is 19.

The square root of 231312331 is about 15208.9556183191. The cubic root of 231312331 is about 613.8556559615.

Adding to 231312331 its reverse (133213132), we get a palindrome (364525463).

The spelling of 231312331 in words is "two hundred thirty-one million, three hundred twelve thousand, three hundred thirty-one".