405805 has 8 divisors (see below), whose sum is σ = 490392. Its totient is φ = 322368.

The previous prime is 405799. The next prime is 405817. The reversal of 405805 is 508504.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 67081 + 338724 = 259^2 + 582^2 .

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 405805 - 2⁷ = 405677 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1239 + ... + 1531.

It is an arithmetic number, because the mean of its divisors is an integer number (61299).

2⁴⁰⁵⁸⁰⁵ is an apocalyptic number.

It is an amenable number.

405805 is a deficient number, since it is larger than the sum of its proper divisors (84587).

405805 is a wasteful number, since it uses less digits than its factorization.

405805 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 575.

The product of its (nonzero) digits is 800, while the sum is 22.

The square root of 405805 is about 637.0282568301. The cubic root of 405805 is about 74.0353495585.

The spelling of 405805 in words is "four hundred five thousand, eight hundred five".