21200012200021 has 32 divisors (see below), whose sum is σ = 22730193100800. Its totient is φ = 19728529007040.

The previous prime is 21200012200001. The next prime is 21200012200099. The reversal of 21200012200021 is 12000221000212.

It is a happy number.

It is a cyclic number.

It is not a de Polignac number, because 21200012200021 - 2⁷ = 21200012199893 is a prime.

It is a super-3 number, since 3×21200012200021³ (a number of 41 digits) contains 333 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21200012199974 and 21200012200010.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21200012200001) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 518735830 + ... + 518776696.

It is an arithmetic number, because the mean of its divisors is an integer number (710318534400).

Almost surely, 2^{21200012200021} is an apocalyptic number.

It is an amenable number.

21200012200021 is a deficient number, since it is larger than the sum of its proper divisors (1530180900779).

21200012200021 is a wasteful number, since it uses less digits than its factorization.

21200012200021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 43249.

The product of its (nonzero) digits is 32, while the sum is 13.

Adding to 21200012200021 its reverse (12000221000212), we get a palindrome (33200233200233).

The spelling of 21200012200021 in words is "twenty-one trillion, two hundred billion, twelve million, two hundred thousand, twenty-one".