728045640 has 96 divisors (see below), whose sum is σ = 2704178880. Its totient is φ = 166409856.

The previous prime is 728045627. The next prime is 728045671. The reversal of 728045640 is 46540827.

728045640 is a `hidden beast` number, since 7 + 2 + 8 + 0 + 4 + 5 + 640 = 666.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a junction number, because it is equal to n+sod(n) for n = 728045595 and 728045604.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 141934 + ... + 146973.

It is an arithmetic number, because the mean of its divisors is an integer number (28168530).

Almost surely, 2^728045640 is an apocalyptic number.

728045640 is a gapful number since it is divisible by the number (70) formed by its first and last digit.

It is an amenable number.

728045640 is an abundant number, since it is smaller than the sum of its proper divisors (1976133240).

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

728045640 is a wasteful number, since it uses less digits than its factorization.

728045640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 288931 (or 288924 counting only the distinct ones).

The product of its (nonzero) digits is 53760, while the sum is 36.

The square root of 728045640 is about 26982.3208786791. The cubic root of 728045640 is about 899.6070877508.

The spelling of 728045640 in words is "seven hundred twenty-eight million, forty-five thousand, six hundred forty".