Adding to 121221211222 its reverse (222112122121), we get a palindrome (343333333343).
It is a sphenic number, since it is the product of 3 distinct primes.
It is a nude number because it is divisible by every one of its digits.
It is a self number, because there is not a number n which added to its sum of digits gives 121221211222.
It is a congruent number.
It is an unprimeable number.
Almost surely, 2121221211222 is an apocalyptic number.
121221211222 is a wasteful number, since it uses less digits than its factorization.
121221211222 is an evil number, because the sum of its binary digits is even.
The sum of its prime factors is 3145742.
The spelling of 121221211222 in words is "one hundred twenty-one billion, two hundred twenty-one million, two hundred eleven thousand, two hundred twenty-two".