1668410321 has 2 divisors, whose sum is σ = 1668410322. Its totient is φ = 1668410320.

The previous prime is 1668410299. The next prime is 1668410323. The reversal of 1668410321 is 1230148661.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1602881296 + 65529025 = 40036^2 + 8095^2 .

It is a cyclic number.

It is not a de Polignac number, because 1668410321 - 2¹⁰ = 1668409297 is a prime.

Together with 1668410323, 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 (1668410323) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 834205160 + 834205161.

It is an arithmetic number, because the mean of its divisors is an integer number (834205161).

Almost surely, 2^1668410321 is an apocalyptic number.

It is an amenable number.

1668410321 is a deficient number, since it is larger than the sum of its proper divisors (1).

1668410321 is an equidigital number, since it uses as much as digits as its factorization.

1668410321 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 6912, while the sum is 32.

The square root of 1668410321 is about 40846.1787808848. The cubic root of 1668410321 is about 1186.0444235536.

Adding to 1668410321 its reverse (1230148661), we get a palindrome (2898558982).

The spelling of 1668410321 in words is "one billion, six hundred sixty-eight million, four hundred ten thousand, three hundred twenty-one".