21222122010221 has 6 divisors (see below), whose sum is σ = 23326795267566. Its totient is φ = 19292838191000.

The previous prime is 21222122010197. The next prime is 21222122010263. The reversal of 21222122010221 is 12201022122212.

It can be written as a sum of positive squares in only one way, i.e., 19343547496900 + 1878574513321 = 4398130^2 + 1370611^2 .

It is not a de Polignac number, because 21222122010221 - 2⁴² = 16824075499117 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 21222122010193 and 21222122010202.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21222122010281) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 87694718930 + ... + 87694719171.

It is an arithmetic number, because the mean of its divisors is an integer number (3887799211261).

Almost surely, 2^{21222122010221} is an apocalyptic number.

It is an amenable number.

21222122010221 is a deficient number, since it is larger than the sum of its proper divisors (2104673257345).

21222122010221 is a wasteful number, since it uses less digits than its factorization.

21222122010221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 175389438123 (or 175389438112 counting only the distinct ones).

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

Adding to 21222122010221 its reverse (12201022122212), we get a palindrome (33423144132433).

The spelling of 21222122010221 in words is "twenty-one trillion, two hundred twenty-two billion, one hundred twenty-two million, ten thousand, two hundred twenty-one".