628809 has 8 divisors (see below), whose sum is σ = 842880. Its totient is φ = 416976.

The previous prime is 628801. The next prime is 628811. The reversal of 628809 is 908826.

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

It is not a de Polignac number, because 628809 - 2³ = 628801 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 628809.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 628809.

It is not an unprimeable number, because it can be changed into a prime (628801) 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, 279 + ... + 1155.

It is an arithmetic number, because the mean of its divisors is an integer number (105360).

2⁶²⁸⁸⁰⁹ is an apocalyptic number.

It is an amenable number.

628809 is a deficient number, since it is larger than the sum of its proper divisors (214071).

628809 is a wasteful number, since it uses less digits than its factorization.

628809 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1119.

The product of its (nonzero) digits is 6912, while the sum is 33.

The square root of 628809 is about 792.9747789180. The cubic root of 628809 is about 85.6721336392.

The spelling of 628809 in words is "six hundred twenty-eight thousand, eight hundred nine".