11212221121121 has 4 divisors (see below), whose sum is σ = 11212588849812. Its totient is φ = 11211853392432.

The previous prime is 11212221121091. The next prime is 11212221121163. The reversal of 11212221121121 is 12112112221211.

It is a happy number.

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 6235328620096 + 4976892501025 = 2497064^2 + 2230895^2 .

It is a cyclic number.

It is not a de Polignac number, because 11212221121121 - 2²² = 11212216926817 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 11212221121093 and 11212221121102.

It is not an unprimeable number, because it can be changed into a prime (11212221121721) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 183818606 + ... + 183879591.

It is an arithmetic number, because the mean of its divisors is an integer number (2803147212453).

Almost surely, 2^{11212221121121} is an apocalyptic number.

It is an amenable number.

11212221121121 is a deficient number, since it is larger than the sum of its proper divisors (367728691).

11212221121121 is an equidigital number, since it uses as much as digits as its factorization.

11212221121121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 367728690.

The product of its digits is 64, while the sum is 20.

Adding to 11212221121121 its reverse (12112112221211), we get a palindrome (23324333342332).

The spelling of 11212221121121 in words is "eleven trillion, two hundred twelve billion, two hundred twenty-one million, one hundred twenty-one thousand, one hundred twenty-one".