221212212112 has 20 divisors (see below), whose sum is σ = 428844894556. Its totient is φ = 110542561920.

The previous prime is 221212212103. The next prime is 221212212113. The reversal of 221212212112 is 211212212122.

221212212112 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 2 ways, for example, as 72574204816 + 148638007296 = 269396^2 + 385536^2 .

It is a nude number because it is divisible by every one of its digits.

It is a self number, because there is not a number n which added to its sum of digits gives 221212212112.

It is not an unprimeable number, because it can be changed into a prime (221212212113) 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 3 ways as a sum of consecutive naturals, for example, 3942783 + ... + 3998494.

Almost surely, 2^221212212112 is an apocalyptic number.

It is an amenable number.

221212212112 is a deficient number, since it is larger than the sum of its proper divisors (207632682444).

221212212112 is a wasteful number, since it uses less digits than its factorization.

221212212112 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7943026 (or 7943020 counting only the distinct ones).

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

Adding to 221212212112 its reverse (211212212122), we get a palindrome (432424424234).

The spelling of 221212212112 in words is "two hundred twenty-one billion, two hundred twelve million, two hundred twelve thousand, one hundred twelve".