720728 has 16 divisors (see below), whose sum is σ = 1410480. Its totient is φ = 344608.

The previous prime is 720703. The next prime is 720743. The reversal of 720728 is 827027.

It is a junction number, because it is equal to n+sod(n) for n = 720697 and 720706.

It is a congruent number.

It is an unprimeable number.

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 3 ways as a sum of consecutive naturals, for example, 1775 + ... + 2142.

It is an arithmetic number, because the mean of its divisors is an integer number (88155).

2⁷²⁰⁷²⁸ is an apocalyptic number.

It is an amenable number.

720728 is a deficient number, since it is larger than the sum of its proper divisors (689752).

720728 is a wasteful number, since it uses less digits than its factorization.

720728 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3946 (or 3942 counting only the distinct ones).

The product of its (nonzero) digits is 1568, while the sum is 26.

The square root of 720728 is about 848.9570071564. The cubic root of 720728 is about 89.6582927432.

The spelling of 720728 in words is "seven hundred twenty thousand, seven hundred twenty-eight".