231644321 has 2 divisors, whose sum is σ = 231644322. Its totient is φ = 231644320.

The previous prime is 231644299. The next prime is 231644323. The reversal of 231644321 is 123446132.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 188925025 + 42719296 = 13745^2 + 6536^2 .

It is a cyclic number.

It is not a de Polignac number, because 231644321 - 2¹⁴ = 231627937 is a prime.

Together with 231644323, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (231644323) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 115822160 + 115822161.

It is an arithmetic number, because the mean of its divisors is an integer number (115822161).

Almost surely, 2^231644321 is an apocalyptic number.

It is an amenable number.

231644321 is a deficient number, since it is larger than the sum of its proper divisors (1).

231644321 is an equidigital number, since it uses as much as digits as its factorization.

231644321 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 3456, while the sum is 26.

The square root of 231644321 is about 15219.8659980960. The cubic root of 231644321 is about 614.1491934452.

The spelling of 231644321 in words is "two hundred thirty-one million, six hundred forty-four thousand, three hundred twenty-one".