21220002202221 has 24 divisors (see below), whose sum is σ = 31995580567704. Its totient is φ = 13538681055360.

The previous prime is 21220002202181. The next prime is 21220002202241. The reversal of 21220002202221 is 12220220002212.

21220002202221 is a `hidden beast` number, since 2 + 1 + 220 + 0 + 0 + 220 + 2 + 221 = 666.

It can be written as a sum of positive squares in 4 ways, for example, as 143997480900 + 21076004721321 = 379470^2 + 4590861^2 .

It is not a de Polignac number, because 21220002202221 - 2¹³ = 21220002194029 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21220002202194 and 21220002202203.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21220002202241) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 522305346 + ... + 522345971.

It is an arithmetic number, because the mean of its divisors is an integer number (1333149190321).

Almost surely, 2^{21220002202221} is an apocalyptic number.

It is an amenable number.

21220002202221 is a deficient number, since it is larger than the sum of its proper divisors (10775578365483).

21220002202221 is a wasteful number, since it uses less digits than its factorization.

21220002202221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1044651421 (or 1044651418 counting only the distinct ones).

The product of its (nonzero) digits is 256, while the sum is 18.

Adding to 21220002202221 its reverse (12220220002212), we get a palindrome (33440222204433).

The spelling of 21220002202221 in words is "twenty-one trillion, two hundred twenty billion, two million, two hundred two thousand, two hundred twenty-one".