409665 has 16 divisors (see below), whose sum is σ = 677376. Its totient is φ = 211200.

The previous prime is 409657. The next prime is 409691. The reversal of 409665 is 566904.

It is not a de Polignac number, because 409665 - 2³ = 409657 is a prime.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (5) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 25 + ... + 905.

It is an arithmetic number, because the mean of its divisors is an integer number (42336).

2⁴⁰⁹⁶⁶⁵ is an apocalyptic number.

It is an amenable number.

409665 is a deficient number, since it is larger than the sum of its proper divisors (267711).

409665 is a wasteful number, since it uses less digits than its factorization.

409665 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 920.

The product of its (nonzero) digits is 6480, while the sum is 30.

The square root of 409665 is about 640.0507792355. The cubic root of 409665 is about 74.2693495581.

The spelling of 409665 in words is "four hundred nine thousand, six hundred sixty-five".