It is a congruent number.
Almost surely, 2121220111220222 is an apocalyptic number.
It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.
121220111220222 is a wasteful number, since it uses less digits than its factorization.
121220111220222 is an odious number, because the sum of its binary digits is odd.
The sum of its prime factors is 70394954304.
Adding to 121220111220222 its reverse (222022111022121), we get a palindrome (343242222242343).
The spelling of 121220111220222 in words is "one hundred twenty-one trillion, two hundred twenty billion, one hundred eleven million, two hundred twenty thousand, two hundred twenty-two".