213320321 has 2 divisors, whose sum is σ = 213320322. Its totient is φ = 213320320.

The previous prime is 213320311. The next prime is 213320323. The reversal of 213320321 is 123023312.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 149719696 + 63600625 = 12236^2 + 7975^2 .

It is a cyclic number.

It is not a de Polignac number, because 213320321 - 2⁶ = 213320257 is a prime.

Together with 213320323, it forms a pair of twin primes.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 213320321.

It is not a weakly prime, because it can be changed into another prime (213320323) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 106660160 + 106660161.

It is an arithmetic number, because the mean of its divisors is an integer number (106660161).

Almost surely, 2^213320321 is an apocalyptic number.

It is an amenable number.

213320321 is a deficient number, since it is larger than the sum of its proper divisors (1).

213320321 is an equidigital number, since it uses as much as digits as its factorization.

213320321 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 216, while the sum is 17.

The square root of 213320321 is about 14605.4894132309. The cubic root of 213320321 is about 597.5084839747.

Adding to 213320321 its reverse (123023312), we get a palindrome (336343633).

The spelling of 213320321 in words is "two hundred thirteen million, three hundred twenty thousand, three hundred twenty-one".