221221222212 has 12 divisors (see below), whose sum is σ = 516182851856. Its totient is φ = 73740407400.

The previous prime is 221221222181. The next prime is 221221222223. The reversal of 221221222212 is 212222122122.

It is a tau number, because it is divible by the number of its divisors (12).

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

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 9217550914 + ... + 9217550937.

Almost surely, 2^221221222212 is an apocalyptic number.

It is an amenable number.

221221222212 is an abundant number, since it is smaller than the sum of its proper divisors (294961629644).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

221221222212 is a wasteful number, since it uses less digits than its factorization.

221221222212 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 18435101858 (or 18435101856 counting only the distinct ones).

The product of its digits is 512, while the sum is 21.

Adding to 221221222212 its reverse (212222122122), we get a palindrome (433443344334).

The spelling of 221221222212 in words is "two hundred twenty-one billion, two hundred twenty-one million, two hundred twenty-two thousand, two hundred twelve".