685921907 has 16 divisors (see below), whose sum is σ = 789360000. Its totient is φ = 589472640.

The previous prime is 685921897. The next prime is 685921913. The reversal of 685921907 is 709129586.

685921907 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a cyclic number.

It is not a de Polignac number, because 685921907 - 2¹⁰ = 685920883 is a prime.

It is not an unprimeable number, because it can be changed into a prime (685921927) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 101003 + ... + 107579.

It is an arithmetic number, because the mean of its divisors is an integer number (49335000).

Almost surely, 2^685921907 is an apocalyptic number.

685921907 is a deficient number, since it is larger than the sum of its proper divisors (103438093).

685921907 is a wasteful number, since it uses less digits than its factorization.

685921907 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7106.

The product of its (nonzero) digits is 272160, while the sum is 47.

The square root of 685921907 is about 26190.1108626901. The cubic root of 685921907 is about 881.9112673249.

The spelling of 685921907 in words is "six hundred eighty-five million, nine hundred twenty-one thousand, nine hundred seven".