687705 has 24 divisors (see below), whose sum is σ = 1170432. Its totient is φ = 344736.

The previous prime is 687691. The next prime is 687707. The reversal of 687705 is 507786.

It is not a de Polignac number, because 687705 - 2⁶ = 687641 is a prime.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (687707) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 5352 + ... + 5478.

It is an arithmetic number, because the mean of its divisors is an integer number (48768).

2⁶⁸⁷⁷⁰⁵ is an apocalyptic number.

It is an amenable number.

687705 is a deficient number, since it is larger than the sum of its proper divisors (482727).

687705 is a wasteful number, since it uses less digits than its factorization.

687705 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 173 (or 154 counting only the distinct ones).

The product of its (nonzero) digits is 11760, while the sum is 33.

The square root of 687705 is about 829.2798080262. The cubic root of 687705 is about 88.2674798921.

The spelling of 687705 in words is "six hundred eighty-seven thousand, seven hundred five".