2021012212221 has 12 divisors (see below), whose sum is σ = 2919265683100. Its totient is φ = 1347329557440.

The previous prime is 2021012212159. The next prime is 2021012212279. The reversal of 2021012212221 is 1222122101202.

It is a happy number.

2021012212221 is a `hidden beast` number, since 20 + 210 + 1 + 2 + 212 + 221 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 1547859456900 + 473152755321 = 1244130^2 + 687861^2 .

It is not a de Polignac number, because 2021012212221 - 2³⁰ = 2019938470397 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 2021012212194 and 2021012212203.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2021012202221) 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, 150201 + ... + 2016081.

Almost surely, 2^{2021012212221} is an apocalyptic number.

It is an amenable number.

2021012212221 is a deficient number, since it is larger than the sum of its proper divisors (898253470879).

2021012212221 is a wasteful number, since it uses less digits than its factorization.

2021012212221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1986236 (or 1986233 counting only the distinct ones).

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

Adding to 2021012212221 its reverse (1222122101202), we get a palindrome (3243134313423).

The spelling of 2021012212221 in words is "two trillion, twenty-one billion, twelve million, two hundred twelve thousand, two hundred twenty-one".