221220221212 has 6 divisors (see below), whose sum is σ = 387135387128. Its totient is φ = 110610110604.

The previous prime is 221220221171. The next prime is 221220221231. The reversal of 221220221212 is 212122022122.

It is a self number, because there is not a number n which added to its sum of digits gives 221220221212.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 27652527648 + ... + 27652527655.

Almost surely, 2^221220221212 is an apocalyptic number.

It is an amenable number.

221220221212 is a deficient number, since it is larger than the sum of its proper divisors (165915165916).

221220221212 is a wasteful number, since it uses less digits than its factorization.

221220221212 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 55305055307 (or 55305055305 counting only the distinct ones).

The product of its (nonzero) digits is 256, while the sum is 19.

Adding to 221220221212 its reverse (212122022122), we get a palindrome (433342243334).

The spelling of 221220221212 in words is "two hundred twenty-one billion, two hundred twenty million, two hundred twenty-one thousand, two hundred twelve".