231320321 has 4 divisors (see below), whose sum is σ = 231472944. Its totient is φ = 231167700.

The previous prime is 231320317. The next prime is 231320329. The reversal of 231320321 is 123023132.

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 231320321 - 2² = 231320317 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 231320321.

It is not an unprimeable number, because it can be changed into a prime (231320329) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 74015 + ... + 77076.

It is an arithmetic number, because the mean of its divisors is an integer number (57868236).

Almost surely, 2^231320321 is an apocalyptic number.

It is an amenable number.

231320321 is a deficient number, since it is larger than the sum of its proper divisors (152623).

231320321 is a wasteful number, since it uses less digits than its factorization.

231320321 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 152622.

The product of its (nonzero) digits is 216, while the sum is 17.

The square root of 231320321 is about 15209.2182902344. The cubic root of 231320321 is about 613.8627238225.

Adding to 231320321 its reverse (123023132), we get a palindrome (354343453).

The spelling of 231320321 in words is "two hundred thirty-one million, three hundred twenty thousand, three hundred twenty-one".