321343021 has 2 divisors, whose sum is σ = 321343022. Its totient is φ = 321343020.

The previous prime is 321343019. The next prime is 321343037. The reversal of 321343021 is 120343123.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 309267396 + 12075625 = 17586^2 + 3475^2 .

It is an emirp because it is prime and its reverse (120343123) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 321343021 - 2¹ = 321343019 is a prime.

It is a super-2 number, since 2×321343021² = 206522674290812882, which contains 22 as substring.

Together with 321343019, it forms a pair of twin primes.

It is a self number, because there is not a number n which added to its sum of digits gives 321343021.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (321313021) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 160671510 + 160671511.

It is an arithmetic number, because the mean of its divisors is an integer number (160671511).

Almost surely, 2^321343021 is an apocalyptic number.

It is an amenable number.

321343021 is a deficient number, since it is larger than the sum of its proper divisors (1).

321343021 is an equidigital number, since it uses as much as digits as its factorization.

321343021 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 432, while the sum is 19.

The square root of 321343021 is about 17926.0430937784. The cubic root of 321343021 is about 684.9459321169.

Adding to 321343021 its reverse (120343123), we get a palindrome (441686144).

The spelling of 321343021 in words is "three hundred twenty-one million, three hundred forty-three thousand, twenty-one".