21101101022221 has 4 divisors (see below), whose sum is σ = 23019382933344. Its totient is φ = 19182819111100.

The previous prime is 21101101022207. The next prime is 21101101022297. The reversal of 21101101022221 is 12222010110112.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 21101101022221 - 2²³ = 21101092633613 is a prime.

It is a super-2 number, since 2×21101101022221² (a number of 27 digits) contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21101101022195 and 21101101022204.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21101101020221) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 959140955545 + ... + 959140955566.

It is an arithmetic number, because the mean of its divisors is an integer number (5754845733336).

Almost surely, 2^{21101101022221} is an apocalyptic number.

It is an amenable number.

21101101022221 is a deficient number, since it is larger than the sum of its proper divisors (1918281911123).

21101101022221 is a wasteful number, since it uses less digits than its factorization.

21101101022221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1918281911122.

The product of its (nonzero) digits is 32, while the sum is 16.

Adding to 21101101022221 its reverse (12222010110112), we get a palindrome (33323111132333).

The spelling of 21101101022221 in words is "twenty-one trillion, one hundred one billion, one hundred one million, twenty-two thousand, two hundred twenty-one".