57728 has 32 divisors (see below), whose sum is σ = 128520. Its totient is φ = 25600.

The previous prime is 57727. The next prime is 57731. The reversal of 57728 is 82775.

It is a tau number, because it is divible by the number of its divisors (32).

It is a zygodrome in base 2.

It is a self number, because there is not a number n which added to its sum of digits gives 57728.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (57727) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (5) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1388 + ... + 1428.

2⁵⁷⁷²⁸ 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 57728, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (64260).

57728 is an abundant number, since it is smaller than the sum of its proper divisors (70792).

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

57728 is a wasteful number, since it uses less digits than its factorization.

57728 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 66 (or 54 counting only the distinct ones).

The product of its digits is 3920, while the sum is 29.

The square root of 57728 is about 240.2665186829. The cubic root of 57728 is about 38.6481613128.

The spelling of 57728 in words is "fifty-seven thousand, seven hundred twenty-eight".