Almost surely, 2121220111221608 is an apocalyptic number.
It is an amenable number.
It is a practical number, because each smaller number is the sum of distinct divisors of 121220111221608, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (174968190552960).
It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.
121220111221608 is a wasteful number, since it uses less digits than its factorization.
121220111221608 is an odious number, because the sum of its binary digits is odd.
Adding to 121220111221608 its reverse (806122111022121), we get a palindrome (927342222243729).
The spelling of 121220111221608 in words is "one hundred twenty-one trillion, two hundred twenty billion, one hundred eleven million, two hundred twenty-one thousand, six hundred eight".