21222223121 has 16 divisors (see below), whose sum is σ = 23710133376. Its totient is φ = 18832800000.

The previous prime is 21222223079. The next prime is 21222223129. The reversal of 21222223121 is 12132222212.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21222223121 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21222223093 and 21222223102.

It is not an unprimeable number, because it can be changed into a prime (21222223129) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 55640 + ... + 213401.

It is an arithmetic number, because the mean of its divisors is an integer number (1481883336).

Almost surely, 2^21222223121 is an apocalyptic number.

It is an amenable number.

21222223121 is a deficient number, since it is larger than the sum of its proper divisors (2487910255).

21222223121 is a wasteful number, since it uses less digits than its factorization.

21222223121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 269224.

The product of its digits is 384, while the sum is 20.

Adding to 21222223121 its reverse (12132222212), we get a palindrome (33354445333).

Subtracting from 21222223121 its reverse (12132222212), we obtain a palindrome (9090000909).

The spelling of 21222223121 in words is "twenty-one billion, two hundred twenty-two million, two hundred twenty-three thousand, one hundred twenty-one".