2021121220221 has 6 divisors (see below), whose sum is σ = 2919397318110. Its totient is φ = 1347414146808.

The previous prime is 2021121220201. The next prime is 2021121220229. The reversal of 2021121220221 is 1220221211202.

It is a happy number.

2021121220221 is a `hidden beast` number, since 2 + 0 + 211 + 212 + 20 + 221 = 666.

It can be written as a sum of positive squares in only one way, i.e., 1927971128196 + 93150092025 = 1388514^2 + 305205^2 .

It is not a de Polignac number, because 2021121220221 - 2¹⁹ = 2021120695933 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 2021121220194 and 2021121220203.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2021121220229) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 112284512226 + ... + 112284512243.

It is an arithmetic number, because the mean of its divisors is an integer number (486566219685).

Almost surely, 2^{2021121220221} is an apocalyptic number.

It is an amenable number.

2021121220221 is a deficient number, since it is larger than the sum of its proper divisors (898276097889).

2021121220221 is a wasteful number, since it uses less digits than its factorization.

2021121220221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 224569024475 (or 224569024472 counting only the distinct ones).

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

Adding to 2021121220221 its reverse (1220221211202), we get a palindrome (3241342431423).

The spelling of 2021121220221 in words is "two trillion, twenty-one billion, one hundred twenty-one million, two hundred twenty thousand, two hundred twenty-one".