728978709 has 8 divisors (see below), whose sum is σ = 972660352. Its totient is φ = 485641440.

The previous prime is 728978687. The next prime is 728978737. The reversal of 728978709 is 907879827.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 728978709 - 2¹² = 728974613 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (728978779) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 81112 + ... + 89649.

It is an arithmetic number, because the mean of its divisors is an integer number (121582544).

Almost surely, 2^728978709 is an apocalyptic number.

It is an amenable number.

728978709 is a deficient number, since it is larger than the sum of its proper divisors (243681643).

728978709 is a wasteful number, since it uses less digits than its factorization.

728978709 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 172187.

The product of its (nonzero) digits is 3556224, while the sum is 57.

The square root of 728978709 is about 26999.6057193434. The cubic root of 728978709 is about 899.9912381863.

The spelling of 728978709 in words is "seven hundred twenty-eight million, nine hundred seventy-eight thousand, seven hundred nine".