21200021010021 has 32 divisors (see below), whose sum is σ = 34205357410560. Its totient is φ = 11401598140416.

The previous prime is 21200021009971. The next prime is 21200021010029. The reversal of 21200021010021 is 12001012000212.

It is not a de Polignac number, because 21200021010021 - 2⁹ = 21200021009509 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21200021009979 and 21200021010006.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21200021010029) 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, 80671125 + ... + 80933493.

It is an arithmetic number, because the mean of its divisors is an integer number (1068917419080).

Almost surely, 2^{21200021010021} is an apocalyptic number.

21200021010021 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

It is an amenable number.

21200021010021 is a deficient number, since it is larger than the sum of its proper divisors (13005336400539).

21200021010021 is a wasteful number, since it uses less digits than its factorization.

21200021010021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 488733.

The product of its (nonzero) digits is 16, while the sum is 12.

Adding to 21200021010021 its reverse (12001012000212), we get a palindrome (33201033010233).

The spelling of 21200021010021 in words is "twenty-one trillion, two hundred billion, twenty-one million, ten thousand, twenty-one".