231538331 has 2 divisors, whose sum is σ = 231538332. Its totient is φ = 231538330.

The previous prime is 231538297. The next prime is 231538339. The reversal of 231538331 is 133835132.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 231538331 - 2¹⁰ = 231537307 is a prime.

It is a super-2 number, since 2×231538331² = 107219997444531122, which contains 22 as substring.

It is a Chen prime.

It is a junction number, because it is equal to n+sod(n) for n = 231538294 and 231538303.

It is not a weakly prime, because it can be changed into another prime (231538339) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 115769165 + 115769166.

It is an arithmetic number, because the mean of its divisors is an integer number (115769166).

Almost surely, 2^231538331 is an apocalyptic number.

231538331 is a deficient number, since it is larger than the sum of its proper divisors (1).

231538331 is an equidigital number, since it uses as much as digits as its factorization.

231538331 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 6480, while the sum is 29.

The square root of 231538331 is about 15216.3836373824. The cubic root of 231538331 is about 614.0555101592.

The spelling of 231538331 in words is "two hundred thirty-one million, five hundred thirty-eight thousand, three hundred thirty-one".