21311223023221 has 8 divisors (see below), whose sum is σ = 21332699176320. Its totient is φ = 21289754779008.

The previous prime is 21311223023191. The next prime is 21311223023239. The reversal of 21311223023221 is 12232032211312.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 21311223023221 - 2¹¹ = 21311223021173 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 (21311223026221) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3422100 + ... + 7371106.

It is an arithmetic number, because the mean of its divisors is an integer number (2666587397040).

Almost surely, 2^{21311223023221} is an apocalyptic number.

It is an amenable number.

21311223023221 is a deficient number, since it is larger than the sum of its proper divisors (21476153099).

21311223023221 is a wasteful number, since it uses less digits than its factorization.

21311223023221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3954443.

The product of its (nonzero) digits is 1728, while the sum is 25.

Adding to 21311223023221 its reverse (12232032211312), we get a palindrome (33543255234533).

The spelling of 21311223023221 in words is "twenty-one trillion, three hundred eleven billion, two hundred twenty-three million, twenty-three thousand, two hundred twenty-one".