731728 has 40 divisors (see below), whose sum is σ = 1562400. Its totient is φ = 330624.

The previous prime is 731719. The next prime is 731729. The reversal of 731728 is 827137.

It is a happy number.

It is a junction number, because it is equal to n+sod(n) for n = 731696 and 731705.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (731729) 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, 8775 + ... + 8857.

It is an arithmetic number, because the mean of its divisors is an integer number (39060).

2⁷³¹⁷²⁸ 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 731728, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (781200).

731728 is an abundant number, since it is smaller than the sum of its proper divisors (830672).

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

731728 is a wasteful number, since it uses less digits than its factorization.

731728 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 139 (or 133 counting only the distinct ones).

The product of its digits is 2352, while the sum is 28.

The square root of 731728 is about 855.4110123210. The cubic root of 731728 is about 90.1121236308.

The spelling of 731728 in words is "seven hundred thirty-one thousand, seven hundred twenty-eight".