121221022121 has 4 divisors (see below), whose sum is σ = 122333141700. Its totient is φ = 120108902544.

The previous prime is 121221022049. The next prime is 121221022127. The reversal of 121221022121 is 121220122121.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 121220122121 = 7 ⋅17317160303.

It can be written as a sum of positive squares in 2 ways, for example, as 109478265625 + 11742756496 = 330875^2 + 108364^2 .

It is a cyclic number.

It is not a de Polignac number, because 121221022121 - 2³⁴ = 104041152937 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 121221022121.

It is not an unprimeable number, because it can be changed into a prime (121221022127) 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, 556059626 + ... + 556059843.

It is an arithmetic number, because the mean of its divisors is an integer number (30583285425).

Almost surely, 2^121221022121 is an apocalyptic number.

It is an amenable number.

121221022121 is a deficient number, since it is larger than the sum of its proper divisors (1112119579).

121221022121 is a wasteful number, since it uses less digits than its factorization.

121221022121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1112119578.

The product of its (nonzero) digits is 64, while the sum is 17.

Adding to 121221022121 its reverse (121220122121), we get a palindrome (242441144242).

The spelling of 121221022121 in words is "one hundred twenty-one billion, two hundred twenty-one million, twenty-two thousand, one hundred twenty-one".