687647685 has 16 divisors (see below), whose sum is σ = 1101219840. Its totient is φ = 366417600.

The previous prime is 687647669. The next prime is 687647747. The reversal of 687647685 is 586746786.

It is not a de Polignac number, because 687647685 - 2⁴ = 687647669 is a prime.

It is a Curzon number.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2650 + ... + 37179.

It is an arithmetic number, because the mean of its divisors is an integer number (68826240).

Almost surely, 2^687647685 is an apocalyptic number.

It is an amenable number.

687647685 is a deficient number, since it is larger than the sum of its proper divisors (413572155).

687647685 is a wasteful number, since it uses less digits than its factorization.

687647685 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 40988.

The product of its digits is 13547520, while the sum is 57.

The square root of 687647685 is about 26223.0372954774. The cubic root of 687647685 is about 882.6502768212.

The spelling of 687647685 in words is "six hundred eighty-seven million, six hundred forty-seven thousand, six hundred eighty-five".