231391 has 8 divisors (see below), whose sum is σ = 244800. Its totient is φ = 218400.

The previous prime is 231379. The next prime is 231409. The reversal of 231391 is 193132.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 231391 - 2⁵ = 231359 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (231331) 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 in 7 ways as a sum of consecutive naturals, for example, 2241 + ... + 2341.

It is an arithmetic number, because the mean of its divisors is an integer number (30600).

2²³¹³⁹¹ is an apocalyptic number.

231391 is a deficient number, since it is larger than the sum of its proper divisors (13409).

231391 is a wasteful number, since it uses less digits than its factorization.

231391 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 209.

The product of its digits is 162, while the sum is 19.

The square root of 231391 is about 481.0311840203. The cubic root of 231391 is about 61.3925238557.

The spelling of 231391 in words is "two hundred thirty-one thousand, three hundred ninety-one".