728673840 has 80 divisors (see below), whose sum is σ = 2509884000. Its totient is φ = 194312448.

The previous prime is 728673821. The next prime is 728673851. The reversal of 728673840 is 48376827.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (80).

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

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 166515 + ... + 170834.

It is an arithmetic number, because the mean of its divisors is an integer number (31373550).

Almost surely, 2^728673840 is an apocalyptic number.

It is an amenable number.

728673840 is an abundant number, since it is smaller than the sum of its proper divisors (1781210160).

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

728673840 is a wasteful number, since it uses less digits than its factorization.

728673840 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 337371 (or 337359 counting only the distinct ones).

The product of its (nonzero) digits is 451584, while the sum is 45.

The square root of 728673840 is about 26993.9593242636. The cubic root of 728673840 is about 899.8657577555.

The spelling of 728673840 in words is "seven hundred twenty-eight million, six hundred seventy-three thousand, eight hundred forty".