728840 has 64 divisors (see below), whose sum is σ = 1987200. Its totient is φ = 235008.

The previous prime is 728839. The next prime is 728843. The reversal of 728840 is 48827.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (728843) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 5252 + ... + 5388.

It is an arithmetic number, because the mean of its divisors is an integer number (31050).

2⁷²⁸⁸⁴⁰ is an apocalyptic number.

728840 is a gapful number since it is divisible by the number (70) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 728840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (993600).

728840 is an abundant number, since it is smaller than the sum of its proper divisors (1258360).

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

728840 is a wasteful number, since it uses less digits than its factorization.

728840 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 174 (or 170 counting only the distinct ones).

The product of its (nonzero) digits is 3584, while the sum is 29.

The square root of 728840 is about 853.7212659879. The cubic root of 728840 is about 89.9934151561.

The spelling of 728840 in words is "seven hundred twenty-eight thousand, eight hundred forty".