686940687 has 24 divisors (see below), whose sum is σ = 1078172160. Its totient is φ = 419858640.

The previous prime is 686940677. The next prime is 686940707. The reversal of 686940687 is 786049686.

686940687 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 686940687 - 2⁶ = 686940623 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (686940677) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 59493 + ... + 70094.

It is an arithmetic number, because the mean of its divisors is an integer number (44923840).

Almost surely, 2^686940687 is an apocalyptic number.

686940687 is a deficient number, since it is larger than the sum of its proper divisors (391231473).

686940687 is a wasteful number, since it uses less digits than its factorization.

686940687 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 129643 (or 129640 counting only the distinct ones).

The product of its (nonzero) digits is 3483648, while the sum is 54.

The square root of 686940687 is about 26209.5533536915. The cubic root of 686940687 is about 882.3476771129.

The spelling of 686940687 in words is "six hundred eighty-six million, nine hundred forty thousand, six hundred eighty-seven".