731328 has 56 divisors (see below), whose sum is σ = 2090928. Its totient is φ = 224256.

The previous prime is 731327. The next prime is 731333. The reversal of 731328 is 823137.

It is a Harshad number since it is a multiple of its sum of digits (24).

It is a junction number, because it is equal to n+sod(n) for n = 731298 and 731307.

It is not an unprimeable number, because it can be changed into a prime (731327) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2350 + ... + 2642.

It is an arithmetic number, because the mean of its divisors is an integer number (37338).

2⁷³¹³²⁸ is an apocalyptic number.

731328 is a gapful number since it is divisible by the number (78) 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 731328, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1045464).

731328 is an abundant number, since it is smaller than the sum of its proper divisors (1359600).

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

731328 is a wasteful number, since it uses less digits than its factorization.

731328 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 321 (or 311 counting only the distinct ones).

The product of its digits is 1008, while the sum is 24.

The square root of 731328 is about 855.1771746252. The cubic root of 731328 is about 90.0957006706.

Subtracting 731328 from its reverse (823137), we obtain a square (91809 = 303²).

The spelling of 731328 in words is "seven hundred thirty-one thousand, three hundred twenty-eight".