687745 has 8 divisors (see below), whose sum is σ = 830016. Its totient is φ = 547056.

The previous prime is 687737. The next prime is 687749. The reversal of 687745 is 547786.

It is a happy number.

687745 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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

It is a cyclic number.

It is not a de Polignac number, because 687745 - 2³ = 687737 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (687749) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1054 + ... + 1576.

It is an arithmetic number, because the mean of its divisors is an integer number (103752).

2⁶⁸⁷⁷⁴⁵ is an apocalyptic number.

It is an amenable number.

687745 is a deficient number, since it is larger than the sum of its proper divisors (142271).

687745 is a wasteful number, since it uses less digits than its factorization.

687745 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 791.

The product of its digits is 47040, while the sum is 37.

The square root of 687745 is about 829.3039249877. The cubic root of 687745 is about 88.2691912028.

The spelling of 687745 in words is "six hundred eighty-seven thousand, seven hundred forty-five".