21022221211221 has 32 divisors (see below), whose sum is σ = 28257483294720. Its totient is φ = 13901305017600.

The previous prime is 21022221211183. The next prime is 21022221211241. The reversal of 21022221211221 is 12211212222012.

It is not a de Polignac number, because 21022221211221 - 2⁶ = 21022221211157 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21022221211241) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 748613901 + ... + 748641981.

It is an arithmetic number, because the mean of its divisors is an integer number (883046352960).

Almost surely, 2^{21022221211221} is an apocalyptic number.

It is an amenable number.

21022221211221 is a deficient number, since it is larger than the sum of its proper divisors (7235262083499).

21022221211221 is a wasteful number, since it uses less digits than its factorization.

21022221211221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 31737.

The product of its (nonzero) digits is 256, while the sum is 21.

Adding to 21022221211221 its reverse (12211212222012), we get a palindrome (33233433433233).

The spelling of 21022221211221 in words is "twenty-one trillion, twenty-two billion, two hundred twenty-one million, two hundred eleven thousand, two hundred twenty-one".