687564 has 36 divisors (see below), whose sum is σ = 1769040. Its totient is φ = 225120.

The previous prime is 687559. The next prime is 687581. The reversal of 687564 is 465786.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (36).

It is a Harshad number since it is a multiple of its sum of digits (36).

It is an Ulam number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 687564.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 2422 + ... + 2690.

It is an arithmetic number, because the mean of its divisors is an integer number (49140).

2⁶⁸⁷⁵⁶⁴ is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 687564, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (884520).

687564 is an abundant number, since it is smaller than the sum of its proper divisors (1081476).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

687564 is a wasteful number, since it uses less digits than its factorization.

687564 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 350 (or 345 counting only the distinct ones).

The product of its digits is 40320, while the sum is 36.

The square root of 687564 is about 829.1947901428. The cubic root of 687564 is about 88.2614469926.

The spelling of 687564 in words is "six hundred eighty-seven thousand, five hundred sixty-four".