820728 has 24 divisors (see below), whose sum is σ = 2223000. Its totient is φ = 273552.

The previous prime is 820723. The next prime is 820733. The reversal of 820728 is 827028.

820728 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is an interprime number because it is at equal distance from previous prime (820723) and next prime (820733).

It is a tau number, because it is divible by the number of its divisors (24).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (820723) by changing a digit.

820728 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 5 ways as a sum of consecutive naturals, for example, 5628 + ... + 5771.

It is an arithmetic number, because the mean of its divisors is an integer number (92625).

2⁸²⁰⁷²⁸ is an apocalyptic number.

It is an amenable number.

820728 is an abundant number, since it is smaller than the sum of its proper divisors (1402272).

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

820728 is a wasteful number, since it uses less digits than its factorization.

820728 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11411 (or 11404 counting only the distinct ones).

The product of its (nonzero) digits is 1792, while the sum is 27.

The square root of 820728 is about 905.9403953903. The cubic root of 820728 is about 93.6267072593.

It can be divided in two parts, 8 and 20728, that added together give a 4-th power (20736 = 12⁴).

The spelling of 820728 in words is "eight hundred twenty thousand, seven hundred twenty-eight".