21220102221221 has 16 divisors (see below), whose sum is σ = 21949021032960. Its totient is φ = 20493989530560.

The previous prime is 21220102221211. The next prime is 21220102221247. The reversal of 21220102221221 is 12212220102212.

It is a cyclic number.

It is not a de Polignac number, because 21220102221221 - 2¹⁰ = 21220102220197 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 = 21220102221193 and 21220102221202.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21220102221211) 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 15 ways as a sum of consecutive naturals, for example, 40814726 + ... + 41331368.

It is an arithmetic number, because the mean of its divisors is an integer number (1371813814560).

Almost surely, 2^{21220102221221} is an apocalyptic number.

It is an amenable number.

21220102221221 is a deficient number, since it is larger than the sum of its proper divisors (728918811739).

21220102221221 is a wasteful number, since it uses less digits than its factorization.

21220102221221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 519356.

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

Adding to 21220102221221 its reverse (12212220102212), we get a palindrome (33432322323433).

The spelling of 21220102221221 in words is "twenty-one trillion, two hundred twenty billion, one hundred two million, two hundred twenty-one thousand, two hundred twenty-one".