21200200021021 has 16 divisors (see below), whose sum is σ = 24385641096064. Its totient is φ = 18053993116224.

The previous prime is 21200200020983. The next prime is 21200200021061. The reversal of 21200200021021 is 12012000200212.

It is a happy number.

It is a cyclic number.

It is not a de Polignac number, because 21200200021021 - 2⁷ = 21200200020893 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21200200020992 and 21200200021010.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21200200021061) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 9705586 + ... + 11687548.

It is an arithmetic number, because the mean of its divisors is an integer number (1524102568504).

Almost surely, 2^{21200200021021} is an apocalyptic number.

It is an amenable number.

21200200021021 is a deficient number, since it is larger than the sum of its proper divisors (3185441075043).

21200200021021 is a wasteful number, since it uses less digits than its factorization.

21200200021021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1991860.

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

Adding to 21200200021021 its reverse (12012000200212), we get a palindrome (33212200221233).

The spelling of 21200200021021 in words is "twenty-one trillion, two hundred billion, two hundred million, twenty-one thousand, twenty-one".