728685 has 12 divisors (see below), whose sum is σ = 1263132. Its totient is φ = 388608.

The previous prime is 728681. The next prime is 728687. The reversal of 728685 is 586827.

It can be written as a sum of positive squares in 2 ways, for example, as 544644 + 184041 = 738^2 + 429^2 .

It is not a de Polignac number, because 728685 - 2² = 728681 is a prime.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (728681) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 8052 + ... + 8141.

It is an arithmetic number, because the mean of its divisors is an integer number (105261).

2⁷²⁸⁶⁸⁵ is an apocalyptic number.

It is an amenable number.

728685 is a deficient number, since it is larger than the sum of its proper divisors (534447).

728685 is a wasteful number, since it uses less digits than its factorization.

728685 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16204 (or 16201 counting only the distinct ones).

The product of its digits is 26880, while the sum is 36.

The square root of 728685 is about 853.6304821174. The cubic root of 728685 is about 89.9870351695.

The spelling of 728685 in words is "seven hundred twenty-eight thousand, six hundred eighty-five".