231550391 has 2 divisors, whose sum is σ = 231550392. Its totient is φ = 231550390.

The previous prime is 231550381. The next prime is 231550393. The reversal of 231550391 is 193055132.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 231550391 - 2¹⁴ = 231534007 is a prime.

Together with 231550393, 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 (231550393) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 115775195 + 115775196.

It is an arithmetic number, because the mean of its divisors is an integer number (115775196).

Almost surely, 2^231550391 is an apocalyptic number.

231550391 is a deficient number, since it is larger than the sum of its proper divisors (1).

231550391 is an equidigital number, since it uses as much as digits as its factorization.

231550391 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 4050, while the sum is 29.

The square root of 231550391 is about 15216.7799156063. The cubic root of 231550391 is about 614.0661712894.

The spelling of 231550391 in words is "two hundred thirty-one million, five hundred fifty thousand, three hundred ninety-one".