1321211220281 has 2 divisors, whose sum is σ = 1321211220282. Its totient is φ = 1321211220280.

The previous prime is 1321211220271. The next prime is 1321211220347. The reversal of 1321211220281 is 1820221121231.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1284008525881 + 37202694400 = 1133141^2 + 192880^2 .

It is a cyclic number.

It is not a de Polignac number, because 1321211220281 - 2¹⁰ = 1321211219257 is a prime.

It is a super-2 number, since 2×1321211220281² (a number of 25 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 1321211220281.

It is not a weakly prime, because it can be changed into another prime (1321211220221) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 660605610140 + 660605610141.

It is an arithmetic number, because the mean of its divisors is an integer number (660605610141).

Almost surely, 2^{1321211220281} is an apocalyptic number.

It is an amenable number.

1321211220281 is a deficient number, since it is larger than the sum of its proper divisors (1).

1321211220281 is an equidigital number, since it uses as much as digits as its factorization.

1321211220281 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 768, while the sum is 26.

The spelling of 1321211220281 in words is "one trillion, three hundred twenty-one billion, two hundred eleven million, two hundred twenty thousand, two hundred eighty-one".