687805 has 8 divisors (see below), whose sum is σ = 831744. Its totient is φ = 546000.

The previous prime is 687787. The next prime is 687809. The reversal of 687805 is 508786.

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

It is not a de Polignac number, because 687805 - 2⁵ = 687773 is a prime.

It is a Duffinian number.

687805 is a lucky number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (687809) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 300 + ... + 1210.

It is an arithmetic number, because the mean of its divisors is an integer number (103968).

2⁶⁸⁷⁸⁰⁵ is an apocalyptic number.

It is an amenable number.

687805 is a deficient number, since it is larger than the sum of its proper divisors (143939).

687805 is a wasteful number, since it uses less digits than its factorization.

687805 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1067.

The product of its (nonzero) digits is 13440, while the sum is 34.

The square root of 687805 is about 829.3400991150. The cubic root of 687805 is about 88.2717580444.

The spelling of 687805 in words is "six hundred eighty-seven thousand, eight hundred five".