21222210021 has 16 divisors (see below), whose sum is σ = 28888056000. Its totient is φ = 13853324160.

The previous prime is 21222210019. The next prime is 21222210059. The reversal of 21222210021 is 12001222212.

It is not a de Polignac number, because 21222210021 - 2¹ = 21222210019 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21222210011) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 54400 + ... + 213081.

It is an arithmetic number, because the mean of its divisors is an integer number (1805503500).

Almost surely, 2^21222210021 is an apocalyptic number.

It is an amenable number.

21222210021 is a deficient number, since it is larger than the sum of its proper divisors (7665845979).

21222210021 is a wasteful number, since it uses less digits than its factorization.

21222210021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 268036.

The product of its (nonzero) digits is 64, while the sum is 15.

Adding to 21222210021 its reverse (12001222212), we get a palindrome (33223432233).

The spelling of 21222210021 in words is "twenty-one billion, two hundred twenty-two million, two hundred ten thousand, twenty-one".