687747 has 4 divisors (see below), whose sum is σ = 917000. Its totient is φ = 458496.

The previous prime is 687737. The next prime is 687749. The reversal of 687747 is 747786.

It is a happy number.

It is a semiprime because it is the product of two primes.

It is not a de Polignac number, because 687747 - 2⁶ = 687683 is a prime.

It is a D-number.

It is a Duffinian number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 687747.

It is not an unprimeable number, because it can be changed into a prime (687749) 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 3 ways as a sum of consecutive naturals, for example, 114622 + ... + 114627.

It is an arithmetic number, because the mean of its divisors is an integer number (229250).

2⁶⁸⁷⁷⁴⁷ is an apocalyptic number.

687747 is a deficient number, since it is larger than the sum of its proper divisors (229253).

687747 is a wasteful number, since it uses less digits than its factorization.

687747 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 229252.

The product of its digits is 65856, while the sum is 39.

The square root of 687747 is about 829.3051308174. The cubic root of 687747 is about 88.2692767666.

Adding to 687747 its sum of digits (39), we get a palindrome (687786).

The spelling of 687747 in words is "six hundred eighty-seven thousand, seven hundred forty-seven".