21328238016 has 168 divisors, whose sum is σ = 61981023104. Its totient is φ = 7011463680.

The previous prime is 21328238011. The next prime is 21328238039. The reversal of 21328238016 is 61083282312.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21328238011) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 18213111 + ... + 18214281.

Almost surely, 2^21328238016 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21328238016, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (30990511552).

21328238016 is an abundant number, since it is smaller than the sum of its proper divisors (40652785088).

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

21328238016 is a wasteful number, since it uses less digits than its factorization.

21328238016 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1599 (or 1586 counting only the distinct ones).

The product of its (nonzero) digits is 27648, while the sum is 36.

The spelling of 21328238016 in words is "twenty-one billion, three hundred twenty-eight million, two hundred thirty-eight thousand, sixteen".