21210101200021 has 8 divisors (see below), whose sum is σ = 21215800985600. Its totient is φ = 21204401868720.

The previous prime is 21210101200003. The next prime is 21210101200051. The reversal of 21210101200021 is 12000210101212.

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

It is a cyclic number.

It is not a de Polignac number, because 21210101200021 - 2⁹ = 21210101199509 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21210101199974 and 21210101200010.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21210101200051) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 106463020 + ... + 106662058.

It is an arithmetic number, because the mean of its divisors is an integer number (2651975123200).

Almost surely, 2^{21210101200021} is an apocalyptic number.

It is an amenable number.

21210101200021 is a deficient number, since it is larger than the sum of its proper divisors (5699785579).

21210101200021 is a wasteful number, since it uses less digits than its factorization.

21210101200021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 227139.

The product of its (nonzero) digits is 16, while the sum is 13.

Adding to 21210101200021 its reverse (12000210101212), we get a palindrome (33210311301233).

The spelling of 21210101200021 in words is "twenty-one trillion, two hundred ten billion, one hundred one million, two hundred thousand, twenty-one".