12111001122221 has 2 divisors, whose sum is σ = 12111001122222. Its totient is φ = 12111001122220.

The previous prime is 12111001122127. The next prime is 12111001122239. The reversal of 12111001122221 is 12222110011121.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 12053992396996 + 57008725225 = 3471886^2 + 238765^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-12111001122221 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 12111001122221.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (12111001122421) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 6055500561110 + 6055500561111.

It is an arithmetic number, because the mean of its divisors is an integer number (6055500561111).

Almost surely, 2^{12111001122221} is an apocalyptic number.

It is an amenable number.

12111001122221 is a deficient number, since it is larger than the sum of its proper divisors (1).

12111001122221 is an equidigital number, since it uses as much as digits as its factorization.

12111001122221 is an odious number, because the sum of its binary digits is odd.

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

Adding to 12111001122221 its reverse (12222110011121), we get a palindrome (24333111133342).

Subtracting 12111001122221 from its reverse (12222110011121), we obtain a square (111108888900 = 333330²).

The spelling of 12111001122221 in words is "twelve trillion, one hundred eleven billion, one million, one hundred twenty-two thousand, two hundred twenty-one".