212211222221 has 4 divisors (see below), whose sum is σ = 212213875200. Its totient is φ = 212208569244.

The previous prime is 212211222193. The next prime is 212211222227. The reversal of 212211222221 is 122222112212.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-212211222221 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 212211222193 and 212211222202.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (212211222227) 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, 1202651 + ... + 1367768.

It is an arithmetic number, because the mean of its divisors is an integer number (53053468800).

Almost surely, 2^212211222221 is an apocalyptic number.

It is an amenable number.

212211222221 is a deficient number, since it is larger than the sum of its proper divisors (2652979).

212211222221 is an equidigital number, since it uses as much as digits as its factorization.

212211222221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2652978.

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

Adding to 212211222221 its reverse (122222112212), we get a palindrome (334433334433).

The spelling of 212211222221 in words is "two hundred twelve billion, two hundred eleven million, two hundred twenty-two thousand, two hundred twenty-one".