406809 has 32 divisors (see below), whose sum is σ = 694400. Its totient is φ = 233280.

The previous prime is 406807. The next prime is 406811. The reversal of 406809 is 908604.

It is an interprime number because it is at equal distance from previous prime (406807) and next prime (406811).

It is not a de Polignac number, because 406809 - 2¹ = 406807 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a Duffinian number.

It is a congruent number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 406809.

It is not an unprimeable number, because it can be changed into a prime (406807) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 6639 + ... + 6699.

It is an arithmetic number, because the mean of its divisors is an integer number (21700).

2⁴⁰⁶⁸⁰⁹ is an apocalyptic number.

It is an amenable number.

406809 is a deficient number, since it is larger than the sum of its proper divisors (287591).

406809 is a wasteful number, since it uses less digits than its factorization.

406809 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 102 (or 96 counting only the distinct ones).

The product of its (nonzero) digits is 1728, while the sum is 27.

The square root of 406809 is about 637.8158041316. The cubic root of 406809 is about 74.0963560961.

The spelling of 406809 in words is "four hundred six thousand, eight hundred nine".