12181231 has 4 divisors (see below), whose sum is σ = 12897792. Its totient is φ = 11464672.

The previous prime is 12181217. The next prime is 12181243. The reversal of 12181231 is 13218121.

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 12181231 - 2⁹ = 12180719 is a prime.

It is a super-2 number, since 2×12181231² = 296764777350722, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 12181199 and 12181208.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (12181271) 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, 358255 + ... + 358288.

It is an arithmetic number, because the mean of its divisors is an integer number (3224448).

Almost surely, 2^12181231 is an apocalyptic number.

12181231 is a deficient number, since it is larger than the sum of its proper divisors (716561).

12181231 is an equidigital number, since it uses as much as digits as its factorization.

12181231 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 716560.

The product of its digits is 96, while the sum is 19.

The square root of 12181231 is about 3490.1620306226. The cubic root of 12181231 is about 230.0896373990.

Adding to 12181231 its reverse (13218121), we get a palindrome (25399352).

The spelling of 12181231 in words is "twelve million, one hundred eighty-one thousand, two hundred thirty-one".