404809 has 4 divisors (see below), whose sum is σ = 406404. Its totient is φ = 403216.

The previous prime is 404783. The next prime is 404819. The reversal of 404809 is 908404.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 126025 + 278784 = 355^2 + 528^2 .

It is a cyclic number.

It is not a de Polignac number, because 404809 - 2¹¹ = 402761 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 (404819) 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, 322 + ... + 955.

It is an arithmetic number, because the mean of its divisors is an integer number (101601).

2⁴⁰⁴⁸⁰⁹ is an apocalyptic number.

It is an amenable number.

404809 is a deficient number, since it is larger than the sum of its proper divisors (1595).

404809 is a wasteful number, since it uses less digits than its factorization.

404809 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1594.

The product of its (nonzero) digits is 1152, while the sum is 25.

The square root of 404809 is about 636.2460215986. The cubic root of 404809 is about 73.9747296231.

It can be divided in two parts, 404 and 809, that multiplied together give a triangular number (326836 = T₈₀₈).

The spelling of 404809 in words is "four hundred four thousand, eight hundred nine".