321313021 has 2 divisors, whose sum is σ = 321313022. Its totient is φ = 321313020.

The previous prime is 321313019. The next prime is 321313033. The reversal of 321313021 is 120313123.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 321305625 + 7396 = 17925^2 + 86^2 .

It is a cyclic number.

It is not a de Polignac number, because 321313021 - 2¹ = 321313019 is a prime.

Together with 321313019, it forms a pair of twin primes.

It is a junction number, because it is equal to n+sod(n) for n = 321312986 and 321313004.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (321313061) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 160656510 + 160656511.

It is an arithmetic number, because the mean of its divisors is an integer number (160656511).

Almost surely, 2^321313021 is an apocalyptic number.

It is an amenable number.

321313021 is a deficient number, since it is larger than the sum of its proper divisors (1).

321313021 is an equidigital number, since it uses as much as digits as its factorization.

321313021 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 108, while the sum is 16.

The square root of 321313021 is about 17925.2063028574. The cubic root of 321313021 is about 684.9246163514.

Adding to 321313021 its reverse (120313123), we get a palindrome (441626144).

The spelling of 321313021 in words is "three hundred twenty-one million, three hundred thirteen thousand, twenty-one".