1212210220121 has 4 divisors (see below), whose sum is σ = 1215174059700. Its totient is φ = 1209246380544.

The previous prime is 1212210220099. The next prime is 1212210220147. The reversal of 1212210220121 is 1210220122121.

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 839402283721 + 372807936400 = 916189^2 + 610580^2 .

It is a cyclic number.

It is not a de Polignac number, because 1212210220121 - 2¹⁰ = 1212210219097 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 1212210220121.

It is not an unprimeable number, because it can be changed into a prime (1212210220021) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1481919176 + ... + 1481919993.

It is an arithmetic number, because the mean of its divisors is an integer number (303793514925).

Almost surely, 2^{1212210220121} is an apocalyptic number.

It is an amenable number.

1212210220121 is a deficient number, since it is larger than the sum of its proper divisors (2963839579).

1212210220121 is an equidigital number, since it uses as much as digits as its factorization.

1212210220121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2963839578.

The product of its (nonzero) digits is 64, while the sum is 17.

Adding to 1212210220121 its reverse (1210220122121), we get a palindrome (2422430342242).

The spelling of 1212210220121 in words is "one trillion, two hundred twelve billion, two hundred ten million, two hundred twenty thousand, one hundred twenty-one".