20921807328 has 192 divisors, whose sum is σ = 58074408000. Its totient is φ = 6585384960.

The previous prime is 20921807323. The next prime is 20921807351. The reversal of 20921807328 is 82370812902.

It is a happy number.

It is a self number, because there is not a number n which added to its sum of digits gives 20921807328.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20921807323) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 59268400 + ... + 59268752.

It is an arithmetic number, because the mean of its divisors is an integer number (302470875).

Almost surely, 2^20921807328 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 20921807328, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (29037204000).

20921807328 is an abundant number, since it is smaller than the sum of its proper divisors (37152600672).

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

20921807328 is a wasteful number, since it uses less digits than its factorization.

20921807328 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 805 (or 797 counting only the distinct ones).

The product of its (nonzero) digits is 96768, while the sum is 42.

The spelling of 20921807328 in words is "twenty billion, nine hundred twenty-one million, eight hundred seven thousand, three hundred twenty-eight".