687861 has 12 divisors (see below), whose sum is σ = 1037088. Its totient is φ = 438504.

The previous prime is 687847. The next prime is 687893. The reversal of 687861 is 168786.

It is not a de Polignac number, because 687861 - 2⁵ = 687829 is a prime.

It is a Curzon number.

It is a congruent number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 687861.

It is not an unprimeable number, because it can be changed into a prime (687061) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 1455 + ... + 1868.

It is an arithmetic number, because the mean of its divisors is an integer number (86424).

2⁶⁸⁷⁸⁶¹ is an apocalyptic number.

It is an amenable number.

687861 is a deficient number, since it is larger than the sum of its proper divisors (349227).

687861 is a wasteful number, since it uses less digits than its factorization.

687861 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3352 (or 3349 counting only the distinct ones).

The product of its digits is 16128, while the sum is 36.

The square root of 687861 is about 829.3738602102. The cubic root of 687861 is about 88.2741536286.

The spelling of 687861 in words is "six hundred eighty-seven thousand, eight hundred sixty-one".