231019331 has 2 divisors, whose sum is σ = 231019332. Its totient is φ = 231019330.

The previous prime is 231019289. The next prime is 231019333. The reversal of 231019331 is 133910132.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-231019331 is a prime.

It is a super-2 number, since 2×231019331² = 106739862591375122, which contains 22 as substring.

Together with 231019333, it forms a pair of twin primes.

It is a Chen prime.

It is a junction number, because it is equal to n+sod(n) for n = 231019297 and 231019306.

It is not a weakly prime, because it can be changed into another prime (231019333) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 115509665 + 115509666.

It is an arithmetic number, because the mean of its divisors is an integer number (115509666).

Almost surely, 2^231019331 is an apocalyptic number.

231019331 is a deficient number, since it is larger than the sum of its proper divisors (1).

231019331 is an equidigital number, since it uses as much as digits as its factorization.

231019331 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 486, while the sum is 23.

The square root of 231019331 is about 15199.3200834774. The cubic root of 231019331 is about 613.5963590737.

Adding to 231019331 its reverse (133910132), we get a palindrome (364929463).

The spelling of 231019331 in words is "two hundred thirty-one million, nineteen thousand, three hundred thirty-one".