686655707 has 4 divisors (see below), whose sum is σ = 710333520. Its totient is φ = 662977896.

The previous prime is 686655703. The next prime is 686655719. The reversal of 686655707 is 707556686.

It is a happy number.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 686655707 - 2² = 686655703 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (686655703) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 11838863 + ... + 11838920.

It is an arithmetic number, because the mean of its divisors is an integer number (177583380).

Almost surely, 2^686655707 is an apocalyptic number.

686655707 is a deficient number, since it is larger than the sum of its proper divisors (23677813).

686655707 is a wasteful number, since it uses less digits than its factorization.

686655707 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 23677812.

The product of its (nonzero) digits is 2116800, while the sum is 50.

The square root of 686655707 is about 26204.1162224563. The cubic root of 686655707 is about 882.2256451211.

The spelling of 686655707 in words is "six hundred eighty-six million, six hundred fifty-five thousand, seven hundred seven".