1604409 has 16 divisors (see below), whose sum is σ = 2290752. Its totient is φ = 995328.

The previous prime is 1604399. The next prime is 1604413. The reversal of 1604409 is 9044061.

It is not a de Polignac number, because 1604409 - 2⁹ = 1603897 is a prime.

It is a Curzon number.

1604409 is a lucky number.

It is not an unprimeable number, because it can be changed into a prime (1604419) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 8217 + ... + 8409.

It is an arithmetic number, because the mean of its divisors is an integer number (143172).

2^1604409 is an apocalyptic number.

It is an amenable number.

1604409 is a deficient number, since it is larger than the sum of its proper divisors (686343).

1604409 is a wasteful number, since it uses less digits than its factorization.

1604409 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 376.

The product of its (nonzero) digits is 864, while the sum is 24.

The square root of 1604409 is about 1266.6526753613. The cubic root of 1604409 is about 117.0680442824.

The spelling of 1604409 in words is "one million, six hundred four thousand, four hundred nine".