804990209 has 4 divisors (see below), whose sum is σ = 805109316. Its totient is φ = 804871104.

The previous prime is 804990203. The next prime is 804990227. The reversal of 804990209 is 902099408.

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 426298609 + 378691600 = 20647^2 + 19460^2 .

It is a cyclic number.

It is not a de Polignac number, because 804990209 - 2⁸ = 804989953 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (804990203) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 48764 + ... + 63149.

It is an arithmetic number, because the mean of its divisors is an integer number (201277329).

Almost surely, 2^804990209 is an apocalyptic number.

It is an amenable number.

804990209 is a deficient number, since it is larger than the sum of its proper divisors (119107).

804990209 is a wasteful number, since it uses less digits than its factorization.

804990209 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 119106.

The product of its (nonzero) digits is 46656, while the sum is 41.

The square root of 804990209 is about 28372.3493739944. The cubic root of 804990209 is about 930.2439753781.

The spelling of 804990209 in words is "eight hundred four million, nine hundred ninety thousand, two hundred nine".