55728 has 50 divisors (see below), whose sum is σ = 165044. Its totient is φ = 18144.

The previous prime is 55721. The next prime is 55733. The reversal of 55728 is 82755.

55728 = 14³ + 15³ + ... + 22³.

It is a happy number.

55728 is digitally balanced in base 2 and base 4, because in such bases it contains all the possibile digits an equal number of times.

It is a Smith number, since the sum of its digits (27) coincides with the sum of the digits of its prime factors.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a nialpdrome in base 3, base 6 and base 9.

It is a zygodrome in base 3 and base 6.

It is not an unprimeable number, because it can be changed into a prime (55721) by changing a digit.

55728 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a polite number, since it can be written in 9 ways as a sum of consecutive naturals, for example, 1275 + ... + 1317.

2⁵⁵⁷²⁸ 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 55728, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (82522).

55728 is an abundant number, since it is smaller than the sum of its proper divisors (109316).

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

55728 is a wasteful number, since it uses less digits than its factorization.

55728 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 63 (or 48 counting only the distinct ones).

The product of its digits is 2800, while the sum is 27.

The square root of 55728 is about 236.0677868749. The cubic root of 55728 is about 38.1965805625.

Adding to 55728 its sum of digits (27), we get a palindrome (55755).

It can be divided in two parts, 557 and 28, that added together give a palindrome (585).

The spelling of 55728 in words is "fifty-five thousand, seven hundred twenty-eight".