121221021221221 has 4 divisors (see below), whose sum is σ = 121221098422444. Its totient is φ = 121220944020000.

The previous prime is 121221021221219. The next prime is 121221021221233. The reversal of 121221021221221 is 122122120122121.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 79784893553121 + 41436127668100 = 8932239^2 + 6437090^2 .

It is a cyclic number.

It is not a de Polignac number, because 121221021221221 - 2¹ = 121221021221219 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 121221021221192 and 121221021221201.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (121221021201221) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (29) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 36195360 + ... + 39402361.

It is an arithmetic number, because the mean of its divisors is an integer number (30305274605611).

Almost surely, 2^{121221021221221} is an apocalyptic number.

It is an amenable number.

121221021221221 is a deficient number, since it is larger than the sum of its proper divisors (77201223).

121221021221221 is an equidigital number, since it uses as much as digits as its factorization.

121221021221221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 77201222.

The product of its (nonzero) digits is 256, while the sum is 22.

Adding to 121221021221221 its reverse (122122120122121), we get a palindrome (243343141343342).

The spelling of 121221021221221 in words is "one hundred twenty-one trillion, two hundred twenty-one billion, twenty-one million, two hundred twenty-one thousand, two hundred twenty-one".