21022022121221 has 16 divisors (see below), whose sum is σ = 23603799429888. Its totient is φ = 18554256705600.

The previous prime is 21022022121181. The next prime is 21022022121241. The reversal of 21022022121221 is 12212122022012.

It is not a de Polignac number, because 21022022121221 - 2¹⁸ = 21022021859077 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21022022121193 and 21022022121202.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21022022121241) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 55590350 + ... + 55967231.

It is an arithmetic number, because the mean of its divisors is an integer number (1475237464368).

Almost surely, 2^{21022022121221} is an apocalyptic number.

It is an amenable number.

21022022121221 is a deficient number, since it is larger than the sum of its proper divisors (2581777308667).

21022022121221 is a wasteful number, since it uses less digits than its factorization.

21022022121221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 111558092.

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

Adding to 21022022121221 its reverse (12212122022012), we get a palindrome (33234144143233).

The spelling of 21022022121221 in words is "twenty-one trillion, twenty-two billion, twenty-two million, one hundred twenty-one thousand, two hundred twenty-one".