686910655 has 16 divisors (see below), whose sum is σ = 836805024. Its totient is φ = 541209600.

The previous prime is 686910649. The next prime is 686910671. The reversal of 686910655 is 556019686.

It is a de Polignac number, because none of the positive numbers 2^k-686910655 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 472680 + ... + 474130.

It is an arithmetic number, because the mean of its divisors is an integer number (52300314).

Almost surely, 2^686910655 is an apocalyptic number.

686910655 is a deficient number, since it is larger than the sum of its proper divisors (149894369).

686910655 is a wasteful number, since it uses less digits than its factorization.

686910655 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2826.

The product of its (nonzero) digits is 388800, while the sum is 46.

The square root of 686910655 is about 26208.9804265637. The cubic root of 686910655 is about 882.3348186269.

The spelling of 686910655 in words is "six hundred eighty-six million, nine hundred ten thousand, six hundred fifty-five".