121020111021221 has 2 divisors, whose sum is σ = 121020111021222. Its totient is φ = 121020111021220.

The previous prime is 121020111020713. The next prime is 121020111021223. The reversal of 121020111021221 is 122120111020121.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 115046432440900 + 5973678580321 = 10725970^2 + 2444111^2 .

It is an emirp because it is prime and its reverse (122120111020121) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 121020111021221 - 2¹⁰ = 121020111020197 is a prime.

It is a super-3 number, since 3×121020111021221³ (a number of 43 digits) contains 333 as substring.

Together with 121020111021223, it forms a pair of twin primes.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 121020111021221.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (121020111021223) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 60510055510610 + 60510055510611.

It is an arithmetic number, because the mean of its divisors is an integer number (60510055510611).

Almost surely, 2^{121020111021221} is an apocalyptic number.

It is an amenable number.

121020111021221 is a deficient number, since it is larger than the sum of its proper divisors (1).

121020111021221 is an equidigital number, since it uses as much as digits as its factorization.

121020111021221 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 121020111021221 its reverse (122120111020121), we get a palindrome (243140222041342).

The spelling of 121020111021221 in words is "one hundred twenty-one trillion, twenty billion, one hundred eleven million, twenty-one thousand, two hundred twenty-one".