604991809 has 2 divisors, whose sum is σ = 604991810. Its totient is φ = 604991808.

The previous prime is 604991791. The next prime is 604991819. The reversal of 604991809 is 908199406.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 604176400 + 815409 = 24580^2 + 903^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-604991809 is a prime.

It is not a weakly prime, because it can be changed into another prime (604991819) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 302495904 + 302495905.

It is an arithmetic number, because the mean of its divisors is an integer number (302495905).

Almost surely, 2^604991809 is an apocalyptic number.

It is an amenable number.

604991809 is a deficient number, since it is larger than the sum of its proper divisors (1).

604991809 is an equidigital number, since it uses as much as digits as its factorization.

604991809 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 139968, while the sum is 46.

The square root of 604991809 is about 24596.5812461813. The cubic root of 604991809 is about 845.7652388828.

The spelling of 604991809 in words is "six hundred four million, nine hundred ninety-one thousand, eight hundred nine".