685900009 has 4 divisors (see below), whose sum is σ = 701851216. Its totient is φ = 669948804.

The previous prime is 685899961. The next prime is 685900013. The reversal of 685900009 is 900009586.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 685900009 - 2⁷ = 685899881 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (685900069) 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 in 3 ways as a sum of consecutive naturals, for example, 7975539 + ... + 7975624.

It is an arithmetic number, because the mean of its divisors is an integer number (175462804).

Almost surely, 2^685900009 is an apocalyptic number.

It is an amenable number.

685900009 is a deficient number, since it is larger than the sum of its proper divisors (15951207).

685900009 is a wasteful number, since it uses less digits than its factorization.

685900009 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15951206.

The product of its (nonzero) digits is 19440, while the sum is 37.

The square root of 685900009 is about 26189.6928007947. The cubic root of 685900009 is about 881.9018822437.

The spelling of 685900009 in words is "six hundred eighty-five million, nine hundred thousand, nine".