21310323221 has 64 divisors (see below), whose sum is σ = 25948339200. Its totient is φ = 17288640000.

The previous prime is 21310323179. The next prime is 21310323247. The reversal of 21310323221 is 12232301312.

It is a cyclic number.

It is not a de Polignac number, because 21310323221 - 2¹⁰ = 21310322197 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21310323193 and 21310323202.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21310320221) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 30839486 + ... + 30840176.

It is an arithmetic number, because the mean of its divisors is an integer number (405442800).

Almost surely, 2^21310323221 is an apocalyptic number.

It is an amenable number.

21310323221 is a deficient number, since it is larger than the sum of its proper divisors (4638015979).

21310323221 is a wasteful number, since it uses less digits than its factorization.

21310323221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 882.

The product of its (nonzero) digits is 432, while the sum is 20.

Adding to 21310323221 its reverse (12232301312), we get a palindrome (33542624533).

The spelling of 21310323221 in words is "twenty-one billion, three hundred ten million, three hundred twenty-three thousand, two hundred twenty-one".