728320320 has 504 divisors, whose sum is σ = 3146185224. Its totient is φ = 153280512.

The previous prime is 728320303. The next prime is 728320337. The reversal of 728320320 is 23023827.

It is an interprime number because it is at equal distance from previous prime (728320303) and next prime (728320337).

It can be written as a sum of positive squares in 4 ways, for example, as 32626944 + 695693376 = 5712^2 + 26376^2 .

It is a tau number, because it is divible by the number of its divisors (504).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 71 ways as a sum of consecutive naturals, for example, 1834362 + ... + 1834758.

It is an arithmetic number, because the mean of its divisors is an integer number (6242431).

Almost surely, 2^728320320 is an apocalyptic number.

728320320 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 728320320, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1573092612).

728320320 is an abundant number, since it is smaller than the sum of its proper divisors (2417864904).

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

728320320 is a wasteful number, since it uses less digits than its factorization.

728320320 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 447 (or 427 counting only the distinct ones).

The product of its (nonzero) digits is 4032, while the sum is 27.

The square root of 728320320 is about 26987.4103981838. The cubic root of 728320320 is about 899.7202093244.

The spelling of 728320320 in words is "seven hundred twenty-eight million, three hundred twenty thousand, three hundred twenty".