21022021201221 has 80 divisors (see below), whose sum is σ = 32496421415040. Its totient is φ = 13535698700160.

The previous prime is 21022021201219. The next prime is 21022021201267. The reversal of 21022021201221 is 12210212022012.

It is a happy number.

21022021201221 is a `hidden beast` number, since 2 + 1 + 0 + 220 + 21 + 201 + 221 = 666.

It is not a de Polignac number, because 21022021201221 - 2¹ = 21022021201219 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21022021201194 and 21022021201203.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21022021201211) by changing a digit.

It is a polite number, since it can be written in 79 ways as a sum of consecutive naturals, for example, 198983550 + ... + 199089168.

It is an arithmetic number, because the mean of its divisors is an integer number (406205267688).

Almost surely, 2^{21022021201221} is an apocalyptic number.

It is an amenable number.

21022021201221 is a deficient number, since it is larger than the sum of its proper divisors (11474400213819).

21022021201221 is a wasteful number, since it uses less digits than its factorization.

21022021201221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 106408 (or 106399 counting only the distinct ones).

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

Adding to 21022021201221 its reverse (12210212022012), we get a palindrome (33232233223233).

The spelling of 21022021201221 in words is "twenty-one trillion, twenty-two billion, twenty-one million, two hundred one thousand, two hundred twenty-one".