231161 has 4 divisors (see below), whose sum is σ = 264192. Its totient is φ = 198132.

The previous prime is 231131. The next prime is 231169. The reversal of 231161 is 161132.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 231161 - 2¹⁰ = 230137 is a prime.

It is an Ulam number.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (231169) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 16505 + ... + 16518.

It is an arithmetic number, because the mean of its divisors is an integer number (66048).

2²³¹¹⁶¹ is an apocalyptic number.

It is an amenable number.

231161 is a deficient number, since it is larger than the sum of its proper divisors (33031).

231161 is an equidigital number, since it uses as much as digits as its factorization.

231161 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 33030.

The product of its digits is 36, while the sum is 14.

The square root of 231161 is about 480.7920548428. The cubic root of 231161 is about 61.3721759575.

Adding to 231161 its reverse (161132), we get a palindrome (392293).

The spelling of 231161 in words is "two hundred thirty-one thousand, one hundred sixty-one".