212211212221 has 4 divisors (see below), whose sum is σ = 212218401244. Its totient is φ = 212204023200.

The previous prime is 212211212207. The next prime is 212211212243. The reversal of 212211212221 is 122212112212.

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 89931612996 + 122279599225 = 299886^2 + 349685^2 .

It is a cyclic number.

It is not a de Polignac number, because 212211212221 - 2¹⁹ = 212210687933 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 (212211210221) 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, 3550050 + ... + 3609331.

It is an arithmetic number, because the mean of its divisors is an integer number (53054600311).

Almost surely, 2^212211212221 is an apocalyptic number.

It is an amenable number.

212211212221 is a deficient number, since it is larger than the sum of its proper divisors (7189023).

212211212221 is an equidigital number, since it uses as much as digits as its factorization.

212211212221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7189022.

The product of its digits is 128, while the sum is 19.

Adding to 212211212221 its reverse (122212112212), we get a palindrome (334423324433).

The spelling of 212211212221 in words is "two hundred twelve billion, two hundred eleven million, two hundred twelve thousand, two hundred twenty-one".