687555 has 32 divisors (see below), whose sum is σ = 1336320. Its totient is φ = 332640.

The previous prime is 687551. The next prime is 687559. The reversal of 687555 is 555786.

It is an interprime number because it is at equal distance from previous prime (687551) and next prime (687559).

It is not a de Polignac number, because 687555 - 2² = 687551 is a prime.

687555 is a lucky number.

It is not an unprimeable number, because it can be changed into a prime (687551) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 1254 + ... + 1716.

It is an arithmetic number, because the mean of its divisors is an integer number (41760).

2⁶⁸⁷⁵⁵⁵ is an apocalyptic number.

687555 is a deficient number, since it is larger than the sum of its proper divisors (648765).

687555 is a wasteful number, since it uses less digits than its factorization.

687555 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 488 (or 482 counting only the distinct ones).

The product of its digits is 42000, while the sum is 36.

The square root of 687555 is about 829.1893631735. The cubic root of 687555 is about 88.2610618859.

Subtracting from 687555 its reverse (555786), we obtain a square (131769 = 363²).

The spelling of 687555 in words is "six hundred eighty-seven thousand, five hundred fifty-five".