321213122221 has 2 divisors, whose sum is σ = 321213122222. Its totient is φ = 321213122220.

The previous prime is 321213122177. The next prime is 321213122267. The reversal of 321213122221 is 122221312123.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 221158575625 + 100054546596 = 470275^2 + 316314^2 .

It is an emirp because it is prime and its reverse (122221312123) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 321213122221 - 2¹⁷ = 321212991149 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 321213122192 and 321213122201.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (321213122291) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 160606561110 + 160606561111.

It is an arithmetic number, because the mean of its divisors is an integer number (160606561111).

Almost surely, 2^321213122221 is an apocalyptic number.

It is an amenable number.

321213122221 is a deficient number, since it is larger than the sum of its proper divisors (1).

321213122221 is an equidigital number, since it uses as much as digits as its factorization.

321213122221 is an evil number, because the sum of its binary digits is even.

The product of its digits is 576, while the sum is 22.

Adding to 321213122221 its reverse (122221312123), we get a palindrome (443434434344).

The spelling of 321213122221 in words is "three hundred twenty-one billion, two hundred thirteen million, one hundred twenty-two thousand, two hundred twenty-one".