21212200000 has 168 divisors, whose sum is σ = 53431830144. Its totient is φ = 8352960000.

The previous prime is 21212199929. The next prime is 21212200013. The reversal of 21212200000 is 221212.

It is a Harshad number since it is a multiple of its sum of digits (10).

It is a self number, because there is not a number n which added to its sum of digits gives 21212200000.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 13399209 + ... + 13400791.

It is an arithmetic number, because the mean of its divisors is an integer number (318046608).

Almost surely, 2^21212200000 is an apocalyptic number.

21212200000 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 21212200000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (26715915072).

21212200000 is an abundant number, since it is smaller than the sum of its proper divisors (32219630144).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21212200000 is an frugal number, since it uses more digits than its factorization.

21212200000 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1687 (or 1657 counting only the distinct ones).

The product of its (nonzero) digits is 16, while the sum is 10.

Adding to 21212200000 its reverse (221212), we get a palindrome (21212421212).

The spelling of 21212200000 in words is "twenty-one billion, two hundred twelve million, two hundred thousand".