21222122200021 has 24 divisors (see below), whose sum is σ = 22580013596616. Its totient is φ = 19941805424640.

The previous prime is 21222122200009. The next prime is 21222122200031. The reversal of 21222122200021 is 12000222122212.

It can be written as a sum of positive squares in 12 ways, for example, as 1933239968100 + 19288882231921 = 1390410^2 + 4391911^2 .

It is not a de Polignac number, because 21222122200021 - 2⁴¹ = 19023098944469 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21222122200031) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 464590035 + ... + 464635711.

It is an arithmetic number, because the mean of its divisors is an integer number (940833899859).

Almost surely, 2^{21222122200021} is an apocalyptic number.

It is an amenable number.

21222122200021 is a deficient number, since it is larger than the sum of its proper divisors (1357891396595).

21222122200021 is a wasteful number, since it uses less digits than its factorization.

21222122200021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 48249 (or 48232 counting only the distinct ones).

The product of its (nonzero) digits is 256, while the sum is 19.

Adding to 21222122200021 its reverse (12000222122212), we get a palindrome (33222344322233).

The spelling of 21222122200021 in words is "twenty-one trillion, two hundred twenty-two billion, one hundred twenty-two million, two hundred thousand, twenty-one".