Adding to 21010000000000 its reverse (1012), we get a palindrome (21010000001012).
It is a congruent number.
It is an unprimeable number.
Almost surely, 221010000000000 is an apocalyptic number.
21010000000000 is a gapful number since it is divisible by the number (20) 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 21010000000000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (28785936910464).
It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.
21010000000000 is an frugal number, since it uses more digits than its factorization.
21010000000000 is an evil number, because the sum of its binary digits is even.