1321211213321 has 2 divisors, whose sum is σ = 1321211213322. Its totient is φ = 1321211213320.

The previous prime is 1321211213269. The next prime is 1321211213323. The reversal of 1321211213321 is 1233121121231.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 758703713296 + 562507500025 = 871036^2 + 750005^2 .

It is a cyclic number.

It is not a de Polignac number, because 1321211213321 - 2¹⁰ = 1321211212297 is a prime.

Together with 1321211213323, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (1321211213323) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 660605606660 + 660605606661.

It is an arithmetic number, because the mean of its divisors is an integer number (660605606661).

Almost surely, 2^{1321211213321} is an apocalyptic number.

It is an amenable number.

1321211213321 is a deficient number, since it is larger than the sum of its proper divisors (1).

1321211213321 is an equidigital number, since it uses as much as digits as its factorization.

1321211213321 is an evil number, because the sum of its binary digits is even.

The product of its digits is 432, while the sum is 23.

Adding to 1321211213321 its reverse (1233121121231), we get a palindrome (2554332334552).

The spelling of 1321211213321 in words is "one trillion, three hundred twenty-one billion, two hundred eleven million, two hundred thirteen thousand, three hundred twenty-one".