728644 has 24 divisors (see below), whose sum is σ = 1487808. Its totient is φ = 305760.

The previous prime is 728639. The next prime is 728647. The reversal of 728644 is 446827.

It is a hoax number, since the sum of its digits (31) coincides with the sum of the digits of its distinct prime factors.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (728647) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1239 + ... + 1729.

It is an arithmetic number, because the mean of its divisors is an integer number (61992).

2⁷²⁸⁶⁴⁴ 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 728644, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (743904).

728644 is an abundant number, since it is smaller than the sum of its proper divisors (759164).

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

728644 is a wasteful number, since it uses less digits than its factorization.

728644 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 555 (or 553 counting only the distinct ones).

The product of its digits is 10752, while the sum is 31.

The square root of 728644 is about 853.6064667047. The cubic root of 728644 is about 89.9853474088.

The spelling of 728644 in words is "seven hundred twenty-eight thousand, six hundred forty-four".