1221211102121 has 2 divisors, whose sum is σ = 1221211102122. Its totient is φ = 1221211102120.

The previous prime is 1221211102081. The next prime is 1221211102183. The reversal of 1221211102121 is 1212011121221.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 834233796496 + 386977305625 = 913364^2 + 622075^2 .

It is an emirp because it is prime and its reverse (1212011121221) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1221211102121 - 2²⁶ = 1221143993257 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 1221211102121.

It is not a weakly prime, because it can be changed into another prime (1221211102421) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 610605551060 + 610605551061.

It is an arithmetic number, because the mean of its divisors is an integer number (610605551061).

Almost surely, 2^{1221211102121} is an apocalyptic number.

It is an amenable number.

1221211102121 is a deficient number, since it is larger than the sum of its proper divisors (1).

1221211102121 is an equidigital number, since it uses as much as digits as its factorization.

1221211102121 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 32, while the sum is 17.

Adding to 1221211102121 its reverse (1212011121221), we get a palindrome (2433222223342).

The spelling of 1221211102121 in words is "one trillion, two hundred twenty-one billion, two hundred eleven million, one hundred two thousand, one hundred twenty-one".