406009 has 4 divisors (see below), whose sum is σ = 409716. Its totient is φ = 402304.

The previous prime is 405997. The next prime is 406013. The reversal of 406009 is 900604.

It is a happy number.

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 51984 + 354025 = 228^2 + 595^2 .

It is a cyclic number.

It is not a de Polignac number, because 406009 - 2⁹ = 405497 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (406309) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1684 + ... + 1909.

It is an arithmetic number, because the mean of its divisors is an integer number (102429).

2⁴⁰⁶⁰⁰⁹ is an apocalyptic number.

It is an amenable number.

406009 is a deficient number, since it is larger than the sum of its proper divisors (3707).

406009 is a wasteful number, since it uses less digits than its factorization.

406009 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3706.

The product of its (nonzero) digits is 216, while the sum is 19.

The square root of 406009 is about 637.1883551981. The cubic root of 406009 is about 74.0477534480.

The spelling of 406009 in words is "four hundred six thousand, nine".