121221220213 has 2 divisors, whose sum is σ = 121221220214. Its totient is φ = 121221220212.

The previous prime is 121221220189. The next prime is 121221220217. The reversal of 121221220213 is 312022122121.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 114093977284 + 7127242929 = 337778^2 + 84423^2 .

It is an emirp because it is prime and its reverse (312022122121) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 121221220213 - 2²¹ = 121219123061 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (121221220217) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 60610610106 + 60610610107.

It is an arithmetic number, because the mean of its divisors is an integer number (60610610107).

Almost surely, 2^121221220213 is an apocalyptic number.

It is an amenable number.

121221220213 is a deficient number, since it is larger than the sum of its proper divisors (1).

121221220213 is an equidigital number, since it uses as much as digits as its factorization.

121221220213 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 192, while the sum is 19.

Adding to 121221220213 its reverse (312022122121), we get a palindrome (433243342334).

The spelling of 121221220213 in words is "one hundred twenty-one billion, two hundred twenty-one million, two hundred twenty thousand, two hundred thirteen".