21011200002000 has 480 divisors, whose sum is σ = 81755330136480. Its totient is φ = 4993641676800.

The previous prime is 21011200001959. The next prime is 21011200002007. The reversal of 21011200002000 is 20000211012.

It can be written as a sum of positive squares in 16 ways, for example, as 20927660504976 + 83539497024 = 4574676^2 + 289032^2 .

It is a Harshad number since it is a multiple of its sum of digits (9).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21011200002007) by changing a digit.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 5237872 + ... + 8334128.

It is an arithmetic number, because the mean of its divisors is an integer number (170323604451).

Almost surely, 2^{21011200002000} is an apocalyptic number.

21011200002000 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 21011200002000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (40877665068240).

21011200002000 is an abundant number, since it is smaller than the sum of its proper divisors (60744130134480).

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

21011200002000 is a wasteful number, since it uses less digits than its factorization.

21011200002000 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3096328 (or 3096309 counting only the distinct ones).

The product of its (nonzero) digits is 8, while the sum is 9.

Adding to 21011200002000 its reverse (20000211012), we get a palindrome (21031200213012).

The spelling of 21011200002000 in words is "twenty-one trillion, eleven billion, two hundred million, two thousand".