405609 has 8 divisors (see below), whose sum is σ = 551232. Its totient is φ = 265200.

The previous prime is 405607. The next prime is 405611. The reversal of 405609 is 906504.

It is an interprime number because it is at equal distance from previous prime (405607) and next prime (405611).

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

It is not a de Polignac number, because 405609 - 2¹ = 405607 is a prime.

It is a Smith number, since the sum of its digits (24) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (405607) 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, 1117 + ... + 1434.

It is an arithmetic number, because the mean of its divisors is an integer number (68904).

2⁴⁰⁵⁶⁰⁹ is an apocalyptic number.

It is an amenable number.

405609 is a deficient number, since it is larger than the sum of its proper divisors (145623).

405609 is a wasteful number, since it uses less digits than its factorization.

405609 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2607.

The product of its (nonzero) digits is 1080, while the sum is 24.

The square root of 405609 is about 636.8743989202. The cubic root of 405609 is about 74.0234281797.

The spelling of 405609 in words is "four hundred five thousand, six hundred nine".