21323320320 has 352 divisors, whose sum is σ = 72894947328. Its totient is φ = 5301338112.

The previous prime is 21323320307. The next prime is 21323320321. The reversal of 21323320320 is 2302332312.

It is not an unprimeable number, because it can be changed into a prime (21323320321) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 33161919 + ... + 33162561.

Almost surely, 2^21323320320 is an apocalyptic number.

21323320320 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21323320320, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (36447473664).

21323320320 is an abundant number, since it is smaller than the sum of its proper divisors (51571627008).

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

21323320320 is a wasteful number, since it uses less digits than its factorization.

21323320320 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 815 (or 797 counting only the distinct ones).

The product of its (nonzero) digits is 1296, while the sum is 21.

Adding to 21323320320 its reverse (2302332312), we get a palindrome (23625652632).

The spelling of 21323320320 in words is "twenty-one billion, three hundred twenty-three million, three hundred twenty thousand, three hundred twenty".