609809 has 2 divisors, whose sum is σ = 609810. Its totient is φ = 609808.

The previous prime is 609803. The next prime is 609821. The reversal of 609809 is 908906.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 494209 + 115600 = 703^2 + 340^2 .

It is a cyclic number.

It is not a de Polignac number, because 609809 - 2¹⁶ = 544273 is a prime.

It is a Sophie Germain prime.

It is a Chen prime.

It is a Curzon number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 609809.

It is not a weakly prime, because it can be changed into another prime (609803) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 304904 + 304905.

It is an arithmetic number, because the mean of its divisors is an integer number (304905).

2⁶⁰⁹⁸⁰⁹ is an apocalyptic number.

It is an amenable number.

609809 is a deficient number, since it is larger than the sum of its proper divisors (1).

609809 is an equidigital number, since it uses as much as digits as its factorization.

609809 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 3888, while the sum is 32.

The square root of 609809 is about 780.9026827973. The cubic root of 609809 is about 84.8004082839.

The spelling of 609809 in words is "six hundred nine thousand, eight hundred nine".