728457840 has 640 divisors, whose sum is σ = 3016949760. Its totient is φ = 159667200.

The previous prime is 728457833. The next prime is 728457881. The reversal of 728457840 is 48754827.

728457840 is a `hidden beast` number, since 72 + 8 + 4 + 578 + 4 + 0 = 666.

728457840 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 127 ways as a sum of consecutive naturals, for example, 16940859 + ... + 16940901.

It is an arithmetic number, because the mean of its divisors is an integer number (4713984).

Almost surely, 2^728457840 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 728457840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1508474880).

728457840 is an abundant number, since it is smaller than the sum of its proper divisors (2288491920).

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

728457840 is a wasteful number, since it uses less digits than its factorization.

728457840 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 130 (or 118 counting only the distinct ones).

The product of its (nonzero) digits is 501760, while the sum is 45.

The square root of 728457840 is about 26989.9581326092. The cubic root of 728457840 is about 899.7768335565.

The spelling of 728457840 in words is "seven hundred twenty-eight million, four hundred fifty-seven thousand, eight hundred forty".