231191 has 4 divisors (see below), whose sum is σ = 234432. Its totient is φ = 227952.

The previous prime is 231169. The next prime is 231197. The reversal of 231191 is 191132.

It is a happy number.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 231191 - 2¹⁴ = 214807 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 (231197) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1511 + ... + 1656.

It is an arithmetic number, because the mean of its divisors is an integer number (58608).

2²³¹¹⁹¹ is an apocalyptic number.

231191 is a deficient number, since it is larger than the sum of its proper divisors (3241).

231191 is an equidigital number, since it uses as much as digits as its factorization.

231191 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3240.

The product of its digits is 54, while the sum is 17.

The square root of 231191 is about 480.8232523496. The cubic root of 231191 is about 61.3748307964.

The spelling of 231191 in words is "two hundred thirty-one thousand, one hundred ninety-one".