1221102112121 has 4 divisors (see below), whose sum is σ = 1221104520612. Its totient is φ = 1221099703632.

The previous prime is 1221102112081. The next prime is 1221102112159. The reversal of 1221102112121 is 1212112011221.

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 332541368896 + 888560743225 = 576664^2 + 942635^2 .

It is a cyclic number.

It is not a de Polignac number, because 1221102112121 - 2⁶ = 1221102112057 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 1221102112121.

It is not an unprimeable number, because it can be changed into a prime (1221102112721) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 115850 + ... + 1567043.

It is an arithmetic number, because the mean of its divisors is an integer number (305276130153).

Almost surely, 2^{1221102112121} is an apocalyptic number.

It is an amenable number.

1221102112121 is a deficient number, since it is larger than the sum of its proper divisors (2408491).

1221102112121 is an equidigital number, since it uses as much as digits as its factorization.

1221102112121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2408490.

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

Adding to 1221102112121 its reverse (1212112011221), we get a palindrome (2433214123342).

The spelling of 1221102112121 in words is "one trillion, two hundred twenty-one billion, one hundred two million, one hundred twelve thousand, one hundred twenty-one".