728321540 has 48 divisors (see below), whose sum is σ = 1586753280. Its totient is φ = 280600320.

The previous prime is 728321537. The next prime is 728321543. The reversal of 728321540 is 45123827.

It is an interprime number because it is at equal distance from previous prime (728321537) and next prime (728321543).

It is a junction number, because it is equal to n+sod(n) for n = 728321497 and 728321506.

It is not an unprimeable number, because it can be changed into a prime (728321543) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 59159 + ... + 70401.

It is an arithmetic number, because the mean of its divisors is an integer number (33057360).

Almost surely, 2^728321540 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 728321540, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (793376640).

728321540 is an abundant number, since it is smaller than the sum of its proper divisors (858431740).

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

728321540 is a wasteful number, since it uses less digits than its factorization.

728321540 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11372 (or 11370 counting only the distinct ones).

The product of its (nonzero) digits is 13440, while the sum is 32.

The square root of 728321540 is about 26987.4330013064. The cubic root of 728321540 is about 899.7207116940.

The spelling of 728321540 in words is "seven hundred twenty-eight million, three hundred twenty-one thousand, five hundred forty".