231665321 has 2 divisors, whose sum is σ = 231665322. Its totient is φ = 231665320.

The previous prime is 231665299. The next prime is 231665327. The reversal of 231665321 is 123566132.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 161290000 + 70375321 = 12700^2 + 8389^2 .

It is a cyclic number.

It is not a de Polignac number, because 231665321 - 2¹⁸ = 231403177 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (231665327) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 115832660 + 115832661.

It is an arithmetic number, because the mean of its divisors is an integer number (115832661).

Almost surely, 2^231665321 is an apocalyptic number.

It is an amenable number.

231665321 is a deficient number, since it is larger than the sum of its proper divisors (1).

231665321 is an equidigital number, since it uses as much as digits as its factorization.

231665321 is an evil number, because the sum of its binary digits is even.

The product of its digits is 6480, while the sum is 29.

The square root of 231665321 is about 15220.5558702697. Note that the first 3 decimals coincide. The cubic root of 231665321 is about 614.1677517005.

The spelling of 231665321 in words is "two hundred thirty-one million, six hundred sixty-five thousand, three hundred twenty-one".