687711 has 4 divisors (see below), whose sum is σ = 916952. Its totient is φ = 458472.

The previous prime is 687707. The next prime is 687721. The reversal of 687711 is 117786.

It is a semiprime because it is the product of two primes.

It is not a de Polignac number, because 687711 - 2² = 687707 is a prime.

It is an Ulam number.

It is a D-number.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (687721) 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, 114616 + ... + 114621.

It is an arithmetic number, because the mean of its divisors is an integer number (229238).

2⁶⁸⁷⁷¹¹ is an apocalyptic number.

687711 is a deficient number, since it is larger than the sum of its proper divisors (229241).

687711 is a wasteful number, since it uses less digits than its factorization.

687711 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 229240.

The product of its digits is 2352, while the sum is 30.

The square root of 687711 is about 829.2834256152. The cubic root of 687711 is about 88.2677365929.

The spelling of 687711 in words is "six hundred eighty-seven thousand, seven hundred eleven".