21221011021221 has 12 divisors (see below), whose sum is σ = 33439168882080. Its totient is φ = 12861218800680.

The previous prime is 21221011021187. The next prime is 21221011021237. The reversal of 21221011021221 is 12212011012212.

21221011021221 is a `hidden beast` number, since 212 + 210 + 1 + 1 + 0 + 21 + 221 = 666.

It is not a de Polignac number, because 21221011021221 - 2³⁹ = 20671255207333 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21221011021194 and 21221011021203.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21221011021241) 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, 107176823241 + ... + 107176823438.

It is an arithmetic number, because the mean of its divisors is an integer number (2786597406840).

Almost surely, 2^{21221011021221} is an apocalyptic number.

It is an amenable number.

21221011021221 is a deficient number, since it is larger than the sum of its proper divisors (12218157860859).

21221011021221 is a wasteful number, since it uses less digits than its factorization.

21221011021221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 214353646696 (or 214353646693 counting only the distinct ones).

The product of its (nonzero) digits is 64, while the sum is 18.

Adding to 21221011021221 its reverse (12212011012212), we get a palindrome (33433022033433).

Subtracting from 21221011021221 its reverse (12212011012212), we obtain a palindrome (9009000009009).

The spelling of 21221011021221 in words is "twenty-one trillion, two hundred twenty-one billion, eleven million, twenty-one thousand, two hundred twenty-one".