21313232320 has 56 divisors (see below), whose sum is σ = 50768329248. Its totient is φ = 8522572800.

The previous prime is 21313232287. The next prime is 21313232321. The reversal of 21313232320 is 2323231312.

It is a junction number, because it is equal to n+sod(n) for n = 21313232291 and 21313232300.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21313232321) 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, 1214005 + ... + 1231435.

It is an arithmetic number, because the mean of its divisors is an integer number (906577308).

Almost surely, 2^21313232320 is an apocalyptic number.

21313232320 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21313232320 is an abundant number, since it is smaller than the sum of its proper divisors (29455096928).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21313232320 is a wasteful number, since it uses less digits than its factorization.

21313232320 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 21269 (or 21259 counting only the distinct ones).

The product of its (nonzero) digits is 1296, while the sum is 22.

Adding to 21313232320 its reverse (2323231312), we get a palindrome (23636463632).

The spelling of 21313232320 in words is "twenty-one billion, three hundred thirteen million, two hundred thirty-two thousand, three hundred twenty".