12121221221111 has 4 divisors (see below), whose sum is σ = 12121968031824. Its totient is φ = 12120474410400.

The previous prime is 12121221221063. The next prime is 12121221221117. The reversal of 12121221221111 is 11112212212121.

It is a happy number.

12121221221111 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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

It is a cyclic number.

It is not a de Polignac number, because 12121221221111 - 2⁶ = 12121221221047 is a prime.

It is a super-2 number, since 2×12121221221111² (a number of 27 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (12121221221117) 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, 373381010 + ... + 373413471.

It is an arithmetic number, because the mean of its divisors is an integer number (3030492007956).

Almost surely, 2^{12121221221111} is an apocalyptic number.

12121221221111 is a deficient number, since it is larger than the sum of its proper divisors (746810713).

12121221221111 is an equidigital number, since it uses as much as digits as its factorization.

12121221221111 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 746810712.

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

Adding to 12121221221111 its reverse (11112212212121), we get a palindrome (23233433433232).

The spelling of 12121221221111 in words is "twelve trillion, one hundred twenty-one billion, two hundred twenty-one million, two hundred twenty-one thousand, one hundred eleven".