221222212221 has 16 divisors (see below), whose sum is σ = 299408760000. Its totient is φ = 145259207808.

The previous prime is 221222212217. The next prime is 221222212229. The reversal of 221222212221 is 122212222122.

It is not a de Polignac number, because 221222212221 - 2² = 221222212217 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (221222212229) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1376905 + ... + 1529153.

It is an arithmetic number, because the mean of its divisors is an integer number (18713047500).

Almost surely, 2^221222212221 is an apocalyptic number.

It is an amenable number.

221222212221 is a deficient number, since it is larger than the sum of its proper divisors (78186547779).

221222212221 is a wasteful number, since it uses less digits than its factorization.

221222212221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 159548.

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

Adding to 221222212221 its reverse (122212222122), we get a palindrome (343434434343).

Subtracting from 221222212221 its reverse (122212222122), we obtain a palindrome (99009990099).

The spelling of 221222212221 in words is "two hundred twenty-one billion, two hundred twenty-two million, two hundred twelve thousand, two hundred twenty-one".