12011221566121 has 4 divisors (see below), whose sum is σ = 12011274378244. Its totient is φ = 12011168754000.

The previous prime is 12011221566101. The next prime is 12011221566131. The reversal of 12011221566121 is 12166512211021.

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 7592565322521 + 4418656243600 = 2755461^2 + 2102060^2 .

It is a cyclic number.

It is not a de Polignac number, because 12011221566121 - 2²⁵ = 12011188011689 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (12011221566101) 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, 26063430 + ... + 26520271.

It is an arithmetic number, because the mean of its divisors is an integer number (3002818594561).

Almost surely, 2^{12011221566121} is an apocalyptic number.

It is an amenable number.

12011221566121 is a deficient number, since it is larger than the sum of its proper divisors (52812123).

12011221566121 is an equidigital number, since it uses as much as digits as its factorization.

12011221566121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 52812122.

The product of its (nonzero) digits is 2880, while the sum is 31.

Adding to 12011221566121 its reverse (12166512211021), we get a palindrome (24177733777142).

The spelling of 12011221566121 in words is "twelve trillion, eleven billion, two hundred twenty-one million, five hundred sixty-six thousand, one hundred twenty-one".