212212122221 has 16 divisors (see below), whose sum is σ = 247548996288. Its totient is φ = 179774112000.

The previous prime is 212212122193. The next prime is 212212122247. The reversal of 212212122221 is 122221212212.

It is a cyclic number.

It is not a de Polignac number, because 212212122221 - 2¹⁰ = 212212121197 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 212212122193 and 212212122202.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (212212124221) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 5599055 + ... + 5636828.

It is an arithmetic number, because the mean of its divisors is an integer number (15471812268).

Almost surely, 2^212212122221 is an apocalyptic number.

It is an amenable number.

212212122221 is a deficient number, since it is larger than the sum of its proper divisors (35336874067).

212212122221 is a wasteful number, since it uses less digits than its factorization.

212212122221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11236012.

The product of its digits is 256, while the sum is 20.

Adding to 212212122221 its reverse (122221212212), we get a palindrome (334433334433).

It can be divided in two parts, 212212 and 122221, that added together give a palindrome (334433).

The spelling of 212212122221 in words is "two hundred twelve billion, two hundred twelve million, one hundred twenty-two thousand, two hundred twenty-one".