687857 has 8 divisors (see below), whose sum is σ = 742560. Its totient is φ = 635040.

The previous prime is 687847. The next prime is 687893. The reversal of 687857 is 758786.

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

It is a cyclic number.

It is not a de Polignac number, because 687857 - 2¹⁸ = 425713 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (41).

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (687847) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 338 + ... + 1220.

It is an arithmetic number, because the mean of its divisors is an integer number (92820).

2⁶⁸⁷⁸⁵⁷ is an apocalyptic number.

It is an amenable number.

687857 is a deficient number, since it is larger than the sum of its proper divisors (54703).

687857 is a wasteful number, since it uses less digits than its factorization.

687857 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 943.

The product of its digits is 94080, while the sum is 41.

The square root of 687857 is about 829.3714487490. The cubic root of 687857 is about 88.2739825197.

The spelling of 687857 in words is "six hundred eighty-seven thousand, eight hundred fifty-seven".