56728 has 16 divisors (see below), whose sum is σ = 121680. Its totient is φ = 24288.

The previous prime is 56713. The next prime is 56731. The reversal of 56728 is 82765.

56728 = 87² + 88² + ... + 93².

It is a Harshad number since it is a multiple of its sum of digits (28).

It is a nialpdrome in base 16.

It is a junction number, because it is equal to n+sod(n) for n = 56696 and 56705.

It is a congruent number.

It is an unprimeable number.

56728 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 3 ways as a sum of consecutive naturals, for example, 451 + ... + 562.

It is an arithmetic number, because the mean of its divisors is an integer number (7605).

2⁵⁶⁷²⁸ is an apocalyptic number.

It is an amenable number.

56728 is an abundant number, since it is smaller than the sum of its proper divisors (64952).

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

It is a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (60840).

56728 is a wasteful number, since it uses less digits than its factorization.

56728 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1026 (or 1022 counting only the distinct ones).

The product of its digits is 3360, while the sum is 28.

The square root of 56728 is about 238.1764052126. The cubic root of 56728 is about 38.4236977567.

It can be divided in two parts, 567 and 28, that multiplied together give a square (15876 = 126²).

The spelling of 56728 in words is "fifty-six thousand, seven hundred twenty-eight".