21220121002221 has 12 divisors (see below), whose sum is σ = 30682215557760. Its totient is φ = 14132472104520.

The previous prime is 21220121002217. The next prime is 21220121002307. The reversal of 21220121002221 is 12220012102212.

It is a happy number.

21220121002221 is a `hidden beast` number, since 212 + 20 + 1 + 210 + 0 + 2 + 221 = 666.

It is not a de Polignac number, because 21220121002221 - 2² = 21220121002217 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21220121002194 and 21220121002203.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21220121002921) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 1189593111 + ... + 1189610948.

It is an arithmetic number, because the mean of its divisors is an integer number (2556851296480).

Almost surely, 2^{21220121002221} is an apocalyptic number.

It is an amenable number.

21220121002221 is a deficient number, since it is larger than the sum of its proper divisors (9462094555539).

21220121002221 is a wasteful number, since it uses less digits than its factorization.

21220121002221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2379205056 (or 2379205053 counting only the distinct ones).

The product of its (nonzero) digits is 128, while the sum is 18.

Adding to 21220121002221 its reverse (12220012102212), we get a palindrome (33440133104433).

The spelling of 21220121002221 in words is "twenty-one trillion, two hundred twenty billion, one hundred twenty-one million, two thousand, two hundred twenty-one".