12111002121221 has 4 divisors (see below), whose sum is σ = 12111053481612. Its totient is φ = 12110950760832.

The previous prime is 12111002121209. The next prime is 12111002121227. The reversal of 12111002121221 is 12212120011121.

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 7059723396196 + 5051278725025 = 2657014^2 + 2247505^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-12111002121221 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 12111002121221.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (12111002121227) 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, 25324850 + ... + 25798643.

It is an arithmetic number, because the mean of its divisors is an integer number (3027763370403).

Almost surely, 2^{12111002121221} is an apocalyptic number.

It is an amenable number.

12111002121221 is a deficient number, since it is larger than the sum of its proper divisors (51360391).

12111002121221 is an equidigital number, since it uses as much as digits as its factorization.

12111002121221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 51360390.

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

Adding to 12111002121221 its reverse (12212120011121), we get a palindrome (24323122132342).

The spelling of 12111002121221 in words is "twelve trillion, one hundred eleven billion, two million, one hundred twenty-one thousand, two hundred twenty-one".