687924 has 36 divisors (see below), whose sum is σ = 1765764. Its totient is φ = 225792.

The previous prime is 687923. The next prime is 687931. The reversal of 687924 is 429786.

It can be written as a sum of positive squares in 2 ways, for example, as 535824 + 152100 = 732^2 + 390^2 .

It is a tau number, because it is divible by the number of its divisors (36).

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (687923) 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, 3394 + ... + 3590.

It is an arithmetic number, because the mean of its divisors is an integer number (49049).

2⁶⁸⁷⁹²⁴ is an apocalyptic number.

It is an amenable number.

687924 is an abundant number, since it is smaller than the sum of its proper divisors (1077840).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

687924 is a wasteful number, since it uses less digits than its factorization.

687924 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 304 (or 299 counting only the distinct ones).

The product of its digits is 24192, while the sum is 36.

The square root of 687924 is about 829.4118397997. The cubic root of 687924 is about 88.2768485053.

It can be divided in two parts, 6879 and 24, that added together give a triangular number (6903 = T₁₁₇).

The spelling of 687924 in words is "six hundred eighty-seven thousand, nine hundred twenty-four".