673809 has 4 divisors (see below), whose sum is σ = 898416. Its totient is φ = 449204.

The previous prime is 673801. The next prime is 673811. The reversal of 673809 is 908376.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 673809 - 2³ = 673801 is a prime.

It is a D-number.

It is a self number, because there is not a number n which added to its sum of digits gives 673809.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 673809.

It is not an unprimeable number, because it can be changed into a prime (673801) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 112299 + ... + 112304.

It is an arithmetic number, because the mean of its divisors is an integer number (224604).

2⁶⁷³⁸⁰⁹ is an apocalyptic number.

It is an amenable number.

673809 is a deficient number, since it is larger than the sum of its proper divisors (224607).

673809 is a wasteful number, since it uses less digits than its factorization.

673809 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 224606.

The product of its (nonzero) digits is 9072, while the sum is 33.

The square root of 673809 is about 820.8586967317. The cubic root of 673809 is about 87.6689091039.

The spelling of 673809 in words is "six hundred seventy-three thousand, eight hundred nine".