21323221233221 has 16 divisors (see below), whose sum is σ = 21512309880000. Its totient is φ = 21134847621888.

The previous prime is 21323221233187. The next prime is 21323221233247. The reversal of 21323221233221 is 12233212232312.

It is a cyclic number.

It is not a de Polignac number, because 21323221233221 - 2¹⁸ = 21323220971077 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21323221233121) 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, 166728326 + ... + 166856168.

It is an arithmetic number, because the mean of its divisors is an integer number (1344519367500).

Almost surely, 2^{21323221233221} is an apocalyptic number.

It is an amenable number.

21323221233221 is a deficient number, since it is larger than the sum of its proper divisors (189088646779).

21323221233221 is a wasteful number, since it uses less digits than its factorization.

21323221233221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 130628.

The product of its digits is 10368, while the sum is 29.

Adding to 21323221233221 its reverse (12233212232312), we get a palindrome (33556433465533).

Subtracting from 21323221233221 its reverse (12233212232312), we obtain a palindrome (9090009000909).

The spelling of 21323221233221 in words is "twenty-one trillion, three hundred twenty-three billion, two hundred twenty-one million, two hundred thirty-three thousand, two hundred twenty-one".