231891 has 8 divisors (see below), whose sum is σ = 337344. Its totient is φ = 140520.

The previous prime is 231877. The next prime is 231893. The reversal of 231891 is 198132.

231891 is digitally balanced in base 7, because in such base it contains all the possibile digits an equal number of times.

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

It is not a de Polignac number, because 231891 - 2⁵ = 231859 is a prime.

231891 is a modest number, since divided by 891 gives 231 as remainder.

231891 is strictly pandigital in base 7.

It is not an unprimeable number, because it can be changed into a prime (231893) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3481 + ... + 3546.

It is an arithmetic number, because the mean of its divisors is an integer number (42168).

2²³¹⁸⁹¹ is an apocalyptic number.

231891 is a deficient number, since it is larger than the sum of its proper divisors (105453).

231891 is a wasteful number, since it uses less digits than its factorization.

231891 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7041.

The product of its digits is 432, while the sum is 24.

The square root of 231891 is about 481.5506203921. The cubic root of 231891 is about 61.4367119449.

The spelling of 231891 in words is "two hundred thirty-one thousand, eight hundred ninety-one".