685721835687 has 16 divisors (see below), whose sum is σ = 1045099520000. Its totient is φ = 391769777952.

The previous prime is 685721835637. The next prime is 685721835767. The reversal of 685721835687 is 786538127586.

It is not a de Polignac number, because 685721835687 - 2¹¹ = 685721833639 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (685721835607) 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, 2851312 + ... + 3082437.

It is an arithmetic number, because the mean of its divisors is an integer number (65318720000).

Almost surely, 2^685721835687 is an apocalyptic number.

685721835687 is a deficient number, since it is larger than the sum of its proper divisors (359377684313).

685721835687 is a wasteful number, since it uses less digits than its factorization.

685721835687 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5939262.

The product of its digits is 135475200, while the sum is 66.

The spelling of 685721835687 in words is "six hundred eighty-five billion, seven hundred twenty-one million, eight hundred thirty-five thousand, six hundred eighty-seven".