2121021220221 has 12 divisors (see below), whose sum is σ = 3063904084800. Its totient is φ = 1413918716040.

The previous prime is 2121021220217. The next prime is 2121021220273. The reversal of 2121021220221 is 1220221201212.

It is a happy number.

2121021220221 is a `hidden beast` number, since 2 + 1 + 210 + 212 + 20 + 221 = 666.

It is not a de Polignac number, because 2121021220221 - 2² = 2121021220217 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 2121021220194 and 2121021220203.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2121091220221) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 7811671 + ... + 8078628.

It is an arithmetic number, because the mean of its divisors is an integer number (255325340400).

Almost surely, 2^{2121021220221} is an apocalyptic number.

It is an amenable number.

2121021220221 is a deficient number, since it is larger than the sum of its proper divisors (942882864579).

2121021220221 is a wasteful number, since it uses less digits than its factorization.

2121021220221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 15905136 (or 15905133 counting only the distinct ones).

The product of its (nonzero) digits is 128, while the sum is 18.

Adding to 2121021220221 its reverse (1220221201212), we get a palindrome (3341242421433).

The spelling of 2121021220221 in words is "two trillion, one hundred twenty-one billion, twenty-one million, two hundred twenty thousand, two hundred twenty-one".