1221321322321 has 2 divisors, whose sum is σ = 1221321322322. Its totient is φ = 1221321322320.

The previous prime is 1221321322271. The next prime is 1221321322339. The reversal of 1221321322321 is 1232231231221.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1022851072321 + 198470250000 = 1011361^2 + 445500^2 .

It is an emirp because it is prime and its reverse (1232231231221) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1221321322321 - 2¹⁵ = 1221321289553 is a prime.

It is not a weakly prime, because it can be changed into another prime (1221321362321) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 610660661160 + 610660661161.

It is an arithmetic number, because the mean of its divisors is an integer number (610660661161).

Almost surely, 2^{1221321322321} is an apocalyptic number.

It is an amenable number.

1221321322321 is a deficient number, since it is larger than the sum of its proper divisors (1).

1221321322321 is an equidigital number, since it uses as much as digits as its factorization.

1221321322321 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1728, while the sum is 25.

Adding to 1221321322321 its reverse (1232231231221), we get a palindrome (2453552553542).

The spelling of 1221321322321 in words is "one trillion, two hundred twenty-one billion, three hundred twenty-one million, three hundred twenty-two thousand, three hundred twenty-one".