1604809 has 2 divisors, whose sum is σ = 1604810. Its totient is φ = 1604808.

The previous prime is 1604753. The next prime is 1604821. The reversal of 1604809 is 9084061.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1149184 + 455625 = 1072^2 + 675^2 .

It is a cyclic number.

It is not a de Polignac number, because 1604809 - 2⁹ = 1604297 is a prime.

It is not a weakly prime, because it can be changed into another prime (1604509) 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 as a sum of consecutive naturals, namely, 802404 + 802405.

It is an arithmetic number, because the mean of its divisors is an integer number (802405).

2^1604809 is an apocalyptic number.

It is an amenable number.

1604809 is a deficient number, since it is larger than the sum of its proper divisors (1).

1604809 is an equidigital number, since it uses as much as digits as its factorization.

1604809 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1728, while the sum is 28.

The square root of 1604809 is about 1266.8105620021. The cubic root of 1604809 is about 117.0777723353.

The spelling of 1604809 in words is "one million, six hundred four thousand, eight hundred nine".