Almost surely, 2121220111221000 is an apocalyptic number.
121220111221000 is a gapful number since it is divisible by the number (10) formed by its first and last digit.
It is an amenable number.
It is a practical number, because each smaller number is the sum of distinct divisors of 121220111221000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (157554004608000).
It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.
121220111221000 is a wasteful number, since it uses less digits than its factorization.
121220111221000 is an evil number, because the sum of its binary digits is even.
Adding to 121220111221000 its reverse (122111022121), we get a palindrome (121342222243121).
The spelling of 121220111221000 in words is "one hundred twenty-one trillion, two hundred twenty billion, one hundred eleven million, two hundred twenty-one thousand".