1212120212221 has 2 divisors, whose sum is σ = 1212120212222. Its totient is φ = 1212120212220.

The previous prime is 1212120212161. The next prime is 1212120212227. The reversal of 1212120212221 is 1222120212121.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 800291268100 + 411828944121 = 894590^2 + 641739^2 .

It is a cyclic number.

It is not a de Polignac number, because 1212120212221 - 2¹⁵ = 1212120179453 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1212120212227) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 606060106110 + 606060106111.

It is an arithmetic number, because the mean of its divisors is an integer number (606060106111).

Almost surely, 2^{1212120212221} is an apocalyptic number.

It is an amenable number.

1212120212221 is a deficient number, since it is larger than the sum of its proper divisors (1).

1212120212221 is an equidigital number, since it uses as much as digits as its factorization.

1212120212221 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 128, while the sum is 19.

Adding to 1212120212221 its reverse (1222120212121), we get a palindrome (2434240424342).

The spelling of 1212120212221 in words is "one trillion, two hundred twelve billion, one hundred twenty million, two hundred twelve thousand, two hundred twenty-one".