212211222021221 has 4 divisors (see below), whose sum is σ = 214089197437452. Its totient is φ = 210333246604992.

The previous prime is 212211222021209. The next prime is 212211222021349. The reversal of 212211222021221 is 122120222112212.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 59018271052225 + 153192950968996 = 7682335^2 + 12377114^2 .

It is a cyclic number.

It is not a de Polignac number, because 212211222021221 - 2³⁰ = 212210148279397 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (212211222027221) 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, 938987707946 + ... + 938987708171.

It is an arithmetic number, because the mean of its divisors is an integer number (53522299359363).

Almost surely, 2^{212211222021221} is an apocalyptic number.

It is an amenable number.

212211222021221 is a deficient number, since it is larger than the sum of its proper divisors (1877975416231).

212211222021221 is a wasteful number, since it uses less digits than its factorization.

212211222021221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1877975416230.

The product of its (nonzero) digits is 512, while the sum is 23.

Adding to 212211222021221 its reverse (122120222112212), we get a palindrome (334331444133433).

Subtracting from 212211222021221 its reverse (122120222112212), we obtain a palindrome (90090999909009).

The spelling of 212211222021221 in words is "two hundred twelve trillion, two hundred eleven billion, two hundred twenty-two million, twenty-one thousand, two hundred twenty-one".