21102222221021 has 16 divisors (see below), whose sum is σ = 21388071513600. Its totient is φ = 20818181886768.

The previous prime is 21102222220997. The next prime is 21102222221023. The reversal of 21102222221021 is 12012222220112.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21102222221021 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21102222220984 and 21102222221002.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21102222221023) 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, 26329616 + ... + 27119238.

It is an arithmetic number, because the mean of its divisors is an integer number (1336754469600).

Almost surely, 2^{21102222221021} is an apocalyptic number.

It is an amenable number.

21102222221021 is a deficient number, since it is larger than the sum of its proper divisors (285849292579).

21102222221021 is a wasteful number, since it uses less digits than its factorization.

21102222221021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 790768.

The product of its (nonzero) digits is 256, while the sum is 20.

Adding to 21102222221021 its reverse (12012222220112), we get a palindrome (33114444441133).

Subtracting from 21102222221021 its reverse (12012222220112), we obtain a palindrome (9090000000909).

The spelling of 21102222221021 in words is "twenty-one trillion, one hundred two billion, two hundred twenty-two million, two hundred twenty-one thousand, twenty-one".