231291 has 12 divisors (see below), whose sum is σ = 345280. Its totient is φ = 149040.

The previous prime is 231289. The next prime is 231293. The reversal of 231291 is 192132.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (231289) and next prime (231293).

It is not a de Polignac number, because 231291 - 2¹ = 231289 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (231293) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 136 + ... + 693.

2²³¹²⁹¹ is an apocalyptic number.

231291 is a deficient number, since it is larger than the sum of its proper divisors (113989).

231291 is a wasteful number, since it uses less digits than its factorization.

231291 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 866 (or 863 counting only the distinct ones).

The product of its digits is 108, while the sum is 18.

The square root of 231291 is about 480.9272294225. The cubic root of 231291 is about 61.3836786010.

The spelling of 231291 in words is "two hundred thirty-one thousand, two hundred ninety-one".