686878 has 8 divisors (see below), whose sum is σ = 1047960. Its totient is φ = 337560.

The previous prime is 686863. The next prime is 686879. The reversal of 686878 is 878686.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (686879) 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, 2793 + ... + 3028.

It is an arithmetic number, because the mean of its divisors is an integer number (130995).

2⁶⁸⁶⁸⁷⁸ is an apocalyptic number.

686878 is a deficient number, since it is larger than the sum of its proper divisors (361082).

686878 is a wasteful number, since it uses less digits than its factorization.

686878 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5882.

The product of its digits is 129024, while the sum is 43.

The square root of 686878 is about 828.7810326015. The cubic root of 686878 is about 88.2320836653.

The spelling of 686878 in words is "six hundred eighty-six thousand, eight hundred seventy-eight".