12001111212221 has 2 divisors, whose sum is σ = 12001111212222. Its totient is φ = 12001111212220.

The previous prime is 12001111212191. The next prime is 12001111212229. The reversal of 12001111212221 is 12221211110021.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 6406538080996 + 5594573131225 = 2531114^2 + 2365285^2 .

It is a cyclic number.

It is not a de Polignac number, because 12001111212221 - 2²² = 12001107017917 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 12001111212221.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (12001111212229) 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 as a sum of consecutive naturals, namely, 6000555606110 + 6000555606111.

It is an arithmetic number, because the mean of its divisors is an integer number (6000555606111).

Almost surely, 2^{12001111212221} is an apocalyptic number.

It is an amenable number.

12001111212221 is a deficient number, since it is larger than the sum of its proper divisors (1).

12001111212221 is an equidigital number, since it uses as much as digits as its factorization.

12001111212221 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 12001111212221 its reverse (12221211110021), we get a palindrome (24222322322242).

The spelling of 12001111212221 in words is "twelve trillion, one billion, one hundred eleven million, two hundred twelve thousand, two hundred twenty-one".