Adding to 22121000022221 its reverse (12222000012122), we get a palindrome (34343000034343).
It is a happy number.
It is a cyclic number.
It is a Duffinian number.
It is a self number, because there is not a number n which added to its sum of digits gives 22121000022221.
It is a congruent number.
Almost surely, 222121000022221 is an apocalyptic number.
It is an amenable number.
22121000022221 is a wasteful number, since it uses less digits than its factorization.
22121000022221 is an odious number, because the sum of its binary digits is odd.
The sum of its prime factors is 44180.
The spelling of 22121000022221 in words is "twenty-two trillion, one hundred twenty-one billion, twenty-two thousand, two hundred twenty-one".