231311321 has 4 divisors (see below), whose sum is σ = 231358992. Its totient is φ = 231263652.

The previous prime is 231311287. The next prime is 231311357. The reversal of 231311321 is 123113132.

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 231311321 - 2⁶ = 231311257 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 231311321.

It is not an unprimeable number, because it can be changed into a prime (231311371) 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, 15611 + ... + 26576.

It is an arithmetic number, because the mean of its divisors is an integer number (57839748).

Almost surely, 2^231311321 is an apocalyptic number.

It is an amenable number.

231311321 is a deficient number, since it is larger than the sum of its proper divisors (47671).

231311321 is an equidigital number, since it uses as much as digits as its factorization.

231311321 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 47670.

The product of its digits is 108, while the sum is 17.

The square root of 231311321 is about 15208.9224141620. The cubic root of 231311321 is about 613.8547625157.

Adding to 231311321 its reverse (123113132), we get a palindrome (354424453).

The spelling of 231311321 in words is "two hundred thirty-one million, three hundred eleven thousand, three hundred twenty-one".