686787 has 4 divisors (see below), whose sum is σ = 915720. Its totient is φ = 457856.

The previous prime is 686773. The next prime is 686789. The reversal of 686787 is 787686.

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 686787 - 2⁶ = 686723 is a prime.

It is an Ulam number.

It is a D-number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 686787.

It is not an unprimeable number, because it can be changed into a prime (686789) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 114462 + ... + 114467.

It is an arithmetic number, because the mean of its divisors is an integer number (228930).

2⁶⁸⁶⁷⁸⁷ is an apocalyptic number.

686787 is a deficient number, since it is larger than the sum of its proper divisors (228933).

686787 is a wasteful number, since it uses less digits than its factorization.

686787 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 228932.

The product of its digits is 112896, while the sum is 42.

The square root of 686787 is about 828.7261308780. The cubic root of 686787 is about 88.2281870616.

The spelling of 686787 in words is "six hundred eighty-six thousand, seven hundred eighty-seven".