20851728552 has 96 divisors (see below), whose sum is σ = 57483691200. Its totient is φ = 6826457088.

The previous prime is 20851728551. The next prime is 20851728571. The reversal of 20851728552 is 25582715802.

20851728552 is a `hidden beast` number, since 2 + 0 + 8 + 517 + 2 + 85 + 52 = 666.

It is a junction number, because it is equal to n+sod(n) for n = 20851728498 and 20851728507.

It is not an unprimeable number, because it can be changed into a prime (20851728551) 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, 7572808 + ... + 7575560.

It is an arithmetic number, because the mean of its divisors is an integer number (598788450).

Almost surely, 2^20851728552 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 20851728552, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (28741845600).

20851728552 is an abundant number, since it is smaller than the sum of its proper divisors (36631962648).

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

20851728552 is a wasteful number, since it uses less digits than its factorization.

20851728552 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4607 (or 4600 counting only the distinct ones).

The product of its (nonzero) digits is 448000, while the sum is 45.

The spelling of 20851728552 in words is "twenty billion, eight hundred fifty-one million, seven hundred twenty-eight thousand, five hundred fifty-two".