Adding to 12121201000000 its reverse (10212121), we get a palindrome (12121211212121).
Almost surely, 212121201000000 is an apocalyptic number.
12121201000000 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 12121201000000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (15055796189592).
It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.
12121201000000 is an frugal number, since it uses more digits than its factorization.
12121201000000 is an evil number, because the sum of its binary digits is even.
The spelling of 12121201000000 in words is "twelve trillion, one hundred twenty-one billion, two hundred one million", and thus it is an aban number.