1211222181121 has 2 divisors, whose sum is σ = 1211222181122. Its totient is φ = 1211222181120.

The previous prime is 1211222181119. The next prime is 1211222181133. The reversal of 1211222181121 is 1211812221121.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1079406713025 + 131815468096 = 1038945^2 + 363064^2 .

It is an emirp because it is prime and its reverse (1211812221121) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1211222181121 - 2¹ = 1211222181119 is a prime.

Together with 1211222181119, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (1211222181151) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 605611090560 + 605611090561.

It is an arithmetic number, because the mean of its divisors is an integer number (605611090561).

Almost surely, 2^{1211222181121} is an apocalyptic number.

It is an amenable number.

1211222181121 is a deficient number, since it is larger than the sum of its proper divisors (1).

1211222181121 is an equidigital number, since it uses as much as digits as its factorization.

1211222181121 is an evil number, because the sum of its binary digits is even.

The product of its digits is 256, while the sum is 25.

The spelling of 1211222181121 in words is "one trillion, two hundred eleven billion, two hundred twenty-two million, one hundred eighty-one thousand, one hundred twenty-one".