687557 has 4 divisors (see below), whose sum is σ = 740460. Its totient is φ = 634656.

The previous prime is 687551. The next prime is 687559. The reversal of 687557 is 755786.

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

It can be written as a sum of positive squares in 2 ways, for example, as 276676 + 410881 = 526^2 + 641^2 .

It is a cyclic number.

It is not a de Polignac number, because 687557 - 2⁴ = 687541 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 687557.

It is a congruent number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 687557.

It is not an unprimeable number, because it can be changed into a prime (687551) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 26432 + ... + 26457.

It is an arithmetic number, because the mean of its divisors is an integer number (185115).

2⁶⁸⁷⁵⁵⁷ is an apocalyptic number.

It is an amenable number.

687557 is a deficient number, since it is larger than the sum of its proper divisors (52903).

687557 is a wasteful number, since it uses less digits than its factorization.

687557 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 52902.

The product of its digits is 58800, while the sum is 38.

The square root of 687557 is about 829.1905691697. The cubic root of 687557 is about 88.2611474655.

The spelling of 687557 in words is "six hundred eighty-seven thousand, five hundred fifty-seven".