212111221221 has 12 divisors (see below), whose sum is σ = 306460866400. Its totient is φ = 141371484840.

The previous prime is 212111221211. The next prime is 212111221297. The reversal of 212111221221 is 122122111212.

212111221221 is a `hidden beast` number, since 212 + 1 + 11 + 221 + 221 = 666.

It is not a de Polignac number, because 212111221221 - 2¹⁹ = 212110696933 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 = 212111221194 and 212111221203.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (212111221211) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 2962321 + ... + 3033078.

Almost surely, 2^212111221221 is an apocalyptic number.

It is an amenable number.

212111221221 is a deficient number, since it is larger than the sum of its proper divisors (94349645179).

212111221221 is a wasteful number, since it uses less digits than its factorization.

212111221221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5999336 (or 5999333 counting only the distinct ones).

The product of its digits is 64, while the sum is 18.

Adding to 212111221221 its reverse (122122111212), we get a palindrome (334233332433).

The spelling of 212111221221 in words is "two hundred twelve billion, one hundred eleven million, two hundred twenty-one thousand, two hundred twenty-one".