728661913 has 24 divisors (see below), whose sum is σ = 905933760. Its totient is φ = 572508000.

The previous prime is 728661911. The next prime is 728661937. The reversal of 728661913 is 319166827.

It is not a de Polignac number, because 728661913 - 2¹ = 728661911 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 728661913.

It is not an unprimeable number, because it can be changed into a prime (728661911) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 124963 + ... + 130663.

It is an arithmetic number, because the mean of its divisors is an integer number (37747240).

Almost surely, 2^728661913 is an apocalyptic number.

It is an amenable number.

728661913 is a deficient number, since it is larger than the sum of its proper divisors (177271847).

728661913 is a wasteful number, since it uses less digits than its factorization.

728661913 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5789 (or 5758 counting only the distinct ones).

The product of its digits is 108864, while the sum is 43.

The square root of 728661913 is about 26993.7384035631. The cubic root of 728661913 is about 899.8608480337.

The spelling of 728661913 in words is "seven hundred twenty-eight million, six hundred sixty-one thousand, nine hundred thirteen".