687305 has 8 divisors (see below), whose sum is σ = 833544. Its totient is φ = 544000.

The previous prime is 687299. The next prime is 687307. The reversal of 687305 is 503786.

It can be written as a sum of positive squares in 4 ways, for example, as 121801 + 565504 = 349^2 + 752^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 687305 - 2⁴ = 687289 is a prime.

It is an Ulam 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 (687307) by changing a digit.

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 7 ways as a sum of consecutive naturals, for example, 176 + ... + 1185.

It is an arithmetic number, because the mean of its divisors is an integer number (104193).

2⁶⁸⁷³⁰⁵ is an apocalyptic number.

It is an amenable number.

687305 is a deficient number, since it is larger than the sum of its proper divisors (146239).

687305 is a wasteful number, since it uses less digits than its factorization.

687305 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1467.

The product of its (nonzero) digits is 5040, while the sum is 29.

The square root of 687305 is about 829.0385998251. The cubic root of 687305 is about 88.2503631344.

The spelling of 687305 in words is "six hundred eighty-seven thousand, three hundred five".