728643 has 8 divisors (see below), whose sum is σ = 982800. Its totient is φ = 480128.

The previous prime is 728639. The next prime is 728647. The reversal of 728643 is 346827.

728643 is nontrivially palindromic in base 7.

728643 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is an interprime number because it is at equal distance from previous prime (728639) and next prime (728647).

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

It is a cyclic number.

It is not a de Polignac number, because 728643 - 2² = 728639 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 728643.

It is not an unprimeable number, because it can be changed into a prime (728647) 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, 1098 + ... + 1631.

It is an arithmetic number, because the mean of its divisors is an integer number (122850).

2⁷²⁸⁶⁴³ is an apocalyptic number.

728643 is a deficient number, since it is larger than the sum of its proper divisors (254157).

728643 is a wasteful number, since it uses less digits than its factorization.

728643 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2821.

The product of its digits is 8064, while the sum is 30.

The square root of 728643 is about 853.6058809544. The cubic root of 728643 is about 89.9853062431.

The spelling of 728643 in words is "seven hundred twenty-eight thousand, six hundred forty-three".