21200012002021 has 8 divisors (see below), whose sum is σ = 21672105523704. Its totient is φ = 20731936297920.

The previous prime is 21200012002007. The next prime is 21200012002063. The reversal of 21200012002021 is 12020021000212.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 332346485025 + 20867665516996 = 576495^2 + 4568114^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21200012002021 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21200012001992 and 21200012002010.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21200012002121) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1004443726 + ... + 1004464831.

It is an arithmetic number, because the mean of its divisors is an integer number (2709013190463).

Almost surely, 2^{21200012002021} is an apocalyptic number.

It is an amenable number.

21200012002021 is a deficient number, since it is larger than the sum of its proper divisors (472093521683).

21200012002021 is a wasteful number, since it uses less digits than its factorization.

21200012002021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2008908791.

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

Adding to 21200012002021 its reverse (12020021000212), we get a palindrome (33220033002233).

The spelling of 21200012002021 in words is "twenty-one trillion, two hundred billion, twelve million, two thousand, twenty-one".