687812 has 12 divisors (see below), whose sum is σ = 1209516. Its totient is φ = 342240.

The previous prime is 687809. The next prime is 687823. The reversal of 687812 is 218786.

It can be written as a sum of positive squares in 2 ways, for example, as 295936 + 391876 = 544^2 + 626^2 .

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 687812.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1262 + ... + 1722.

It is an arithmetic number, because the mean of its divisors is an integer number (100793).

2⁶⁸⁷⁸¹² is an apocalyptic number.

It is an amenable number.

687812 is a deficient number, since it is larger than the sum of its proper divisors (521704).

687812 is a wasteful number, since it uses less digits than its factorization.

687812 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 838 (or 836 counting only the distinct ones).

The product of its digits is 5376, while the sum is 32.

The square root of 687812 is about 829.3443193270. The cubic root of 687812 is about 88.2720574995.

The spelling of 687812 in words is "six hundred eighty-seven thousand, eight hundred twelve".