728307605 has 4 divisors (see below), whose sum is σ = 873969132. Its totient is φ = 582646080.

The previous prime is 728307599. The next prime is 728307661. The reversal of 728307605 is 506703827.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 506703827 = 7 ⋅72386261.

It can be written as a sum of positive squares in 2 ways, for example, as 515789521 + 212518084 = 22711^2 + 14578^2 .

It is a de Polignac number, because none of the positive numbers 2^k-728307605 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 72830756 + ... + 72830765.

It is an arithmetic number, because the mean of its divisors is an integer number (218492283).

Almost surely, 2^728307605 is an apocalyptic number.

It is an amenable number.

728307605 is a deficient number, since it is larger than the sum of its proper divisors (145661527).

728307605 is a wasteful number, since it uses less digits than its factorization.

728307605 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 145661526.

The product of its (nonzero) digits is 70560, while the sum is 38.

The square root of 728307605 is about 26987.1748243494. The cubic root of 728307605 is about 899.7149735288.

The spelling of 728307605 in words is "seven hundred twenty-eight million, three hundred seven thousand, six hundred five".