21123332320 has 96 divisors (see below), whose sum is σ = 53836731648. Its totient is φ = 7802216448.

The previous prime is 21123332317. The next prime is 21123332369. The reversal of 21123332320 is 2323332112.

It is a junction number, because it is equal to n+sod(n) for n = 21123332291 and 21123332300.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 70897 + ... + 217423.

It is an arithmetic number, because the mean of its divisors is an integer number (560799288).

Almost surely, 2^21123332320 is an apocalyptic number.

21123332320 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 21123332320, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (26918365824).

21123332320 is an abundant number, since it is smaller than the sum of its proper divisors (32713399328).

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

21123332320 is a wasteful number, since it uses less digits than its factorization.

21123332320 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 146612 (or 146604 counting only the distinct ones).

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

Adding to 21123332320 its reverse (2323332112), we get a palindrome (23446664432).

The spelling of 21123332320 in words is "twenty-one billion, one hundred twenty-three million, three hundred thirty-two thousand, three hundred twenty".