121220112121021 has 4 divisors (see below), whose sum is σ = 121220134177500. Its totient is φ = 121220090064544.

The previous prime is 121220112120971. The next prime is 121220112121039. The reversal of 121220112121021 is 120121211022121.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It can be written as a sum of positive squares in 2 ways, for example, as 105262244348121 + 15957867772900 = 10259739^2 + 3994730^2 .

It is a cyclic number.

It is not a de Polignac number, because 121220112121021 - 2⁴³ = 112424019098813 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 121220112121021.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (121220112121081) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 4563135 + ... + 16225363.

It is an arithmetic number, because the mean of its divisors is an integer number (30305033544375).

Almost surely, 2^{121220112121021} is an apocalyptic number.

It is an amenable number.

121220112121021 is a deficient number, since it is larger than the sum of its proper divisors (22056479).

121220112121021 is a wasteful number, since it uses less digits than its factorization.

121220112121021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 22056478.

The product of its (nonzero) digits is 64, while the sum is 19.

Adding to 121220112121021 its reverse (120121211022121), we get a palindrome (241341323143142).

The spelling of 121220112121021 in words is "one hundred twenty-one trillion, two hundred twenty billion, one hundred twelve million, one hundred twenty-one thousand, twenty-one".