239431391 has 2 divisors, whose sum is σ = 239431392. Its totient is φ = 239431390.

The previous prime is 239431351. The next prime is 239431393. The reversal of 239431391 is 193134932.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 239431391 - 2⁶ = 239431327 is a prime.

Together with 239431393, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (239431393) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 119715695 + 119715696.

It is an arithmetic number, because the mean of its divisors is an integer number (119715696).

Almost surely, 2^239431391 is an apocalyptic number.

239431391 is a deficient number, since it is larger than the sum of its proper divisors (1).

239431391 is an equidigital number, since it uses as much as digits as its factorization.

239431391 is an evil number, because the sum of its binary digits is even.

The product of its digits is 17496, while the sum is 35.

The square root of 239431391 is about 15473.5707255953. The cubic root of 239431391 is about 620.9553352155.

The spelling of 239431391 in words is "two hundred thirty-nine million, four hundred thirty-one thousand, three hundred ninety-one".