Adding to 21111002000 its reverse (20011112), we get a palindrome (21131013112).
It is an unprimeable number.
Almost surely, 221111002000 is an apocalyptic number.
21111002000 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 21111002000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (28301742144).
It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.
21111002000 is a wasteful number, since it uses less digits than its factorization.
21111002000 is an evil number, because the sum of its binary digits is even.
The spelling of 21111002000 in words is "twenty-one billion, one hundred eleven million, two thousand".