406409 has 4 divisors (see below), whose sum is σ = 415104. Its totient is φ = 397716.

The previous prime is 406403. The next prime is 406423. The reversal of 406409 is 904604.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 406409 - 2¹² = 402313 is a prime.

It is an Ulam number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (406403) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 4277 + ... + 4370.

It is an arithmetic number, because the mean of its divisors is an integer number (103776).

2⁴⁰⁶⁴⁰⁹ is an apocalyptic number.

It is an amenable number.

406409 is a deficient number, since it is larger than the sum of its proper divisors (8695).

406409 is an equidigital number, since it uses as much as digits as its factorization.

406409 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8694.

The product of its (nonzero) digits is 864, while the sum is 23.

The square root of 406409 is about 637.5021568591. The cubic root of 406409 is about 74.0720627448.

The spelling of 406409 in words is "four hundred six thousand, four hundred nine".