1212211111121 has 4 divisors (see below), whose sum is σ = 1235083018932. Its totient is φ = 1189339203312.

The previous prime is 1212211111087. The next prime is 1212211111129. The reversal of 1212211111121 is 1211111122121.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 406814352400 + 805396758721 = 637820^2 + 897439^2 .

It is a cyclic number.

It is not a de Polignac number, because 1212211111121 - 2¹⁴ = 1212211094737 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 1212211111121.

It is not an unprimeable number, because it can be changed into a prime (1212211111129) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 11435953826 + ... + 11435953931.

It is an arithmetic number, because the mean of its divisors is an integer number (308770754733).

Almost surely, 2^{1212211111121} is an apocalyptic number.

It is an amenable number.

1212211111121 is a deficient number, since it is larger than the sum of its proper divisors (22871907811).

1212211111121 is an equidigital number, since it uses as much as digits as its factorization.

1212211111121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 22871907810.

The product of its digits is 16, while the sum is 17.

Adding to 1212211111121 its reverse (1211111122121), we get a palindrome (2423322233242).

The spelling of 1212211111121 in words is "one trillion, two hundred twelve billion, two hundred eleven million, one hundred eleven thousand, one hundred twenty-one".