Adding to 121220220 its reverse (22022121), we get a palindrome (143242341).
It is a congruent number.
It is an unprimeable number.
Almost surely, 2121220220 is an apocalyptic number.
121220220 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 121220220, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (190370880).
It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.
121220220 is a wasteful number, since it uses less digits than its factorization.
121220220 is an evil number, because the sum of its binary digits is even.
The square root of 121220220 is about 11010.0054495899. The cubic root of 121220220 is about 494.9086251089.
The spelling of 121220220 in words is "one hundred twenty-one million, two hundred twenty thousand, two hundred twenty".