231868591 has 2 divisors, whose sum is σ = 231868592. Its totient is φ = 231868590.

The previous prime is 231868573. The next prime is 231868597. The reversal of 231868591 is 195868132.

231868591 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 231868591 - 2¹¹ = 231866543 is a prime.

It is equal to p_12739678 and since 231868591 and 12739678 have the same sum of digits, it is a Honaker prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (231868597) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 115934295 + 115934296.

It is an arithmetic number, because the mean of its divisors is an integer number (115934296).

Almost surely, 2^231868591 is an apocalyptic number.

231868591 is a deficient number, since it is larger than the sum of its proper divisors (1).

231868591 is an equidigital number, since it uses as much as digits as its factorization.

231868591 is an evil number, because the sum of its binary digits is even.

The product of its digits is 103680, while the sum is 43.

The square root of 231868591 is about 15227.2318889547. The cubic root of 231868591 is about 614.3473288348.

The spelling of 231868591 in words is "two hundred thirty-one million, eight hundred sixty-eight thousand, five hundred ninety-one".