685720911 has 16 divisors (see below), whose sum is σ = 928309248. Its totient is φ = 450156000.

The previous prime is 685720909. The next prime is 685720933. The reversal of 685720911 is 119027586.

It is not a de Polignac number, because 685720911 - 2¹ = 685720909 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 685720911.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (685724911) 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 15 ways as a sum of consecutive naturals, for example, 243765 + ... + 246561.

It is an arithmetic number, because the mean of its divisors is an integer number (58019328).

Almost surely, 2^685720911 is an apocalyptic number.

685720911 is a deficient number, since it is larger than the sum of its proper divisors (242588337).

685720911 is a wasteful number, since it uses less digits than its factorization.

685720911 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4022.

The product of its (nonzero) digits is 30240, while the sum is 39.

The square root of 685720911 is about 26186.2733316522. The cubic root of 685720911 is about 881.8251166265.

The spelling of 685720911 in words is "six hundred eighty-five million, seven hundred twenty thousand, nine hundred eleven".