687939 has 32 divisors (see below), whose sum is σ = 1161216. Its totient is φ = 353280.

The previous prime is 687931. The next prime is 687949. The reversal of 687939 is 939786.

It is a happy number.

It is not a de Polignac number, because 687939 - 2³ = 687931 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 687939.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (687931) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 14614 + ... + 14660.

It is an arithmetic number, because the mean of its divisors is an integer number (36288).

2⁶⁸⁷⁹³⁹ is an apocalyptic number.

687939 is a deficient number, since it is larger than the sum of its proper divisors (473277).

687939 is a wasteful number, since it uses less digits than its factorization.

687939 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 115.

The product of its digits is 81648, while the sum is 42.

The square root of 687939 is about 829.4208823028. The cubic root of 687939 is about 88.2774901184.

The spelling of 687939 in words is "six hundred eighty-seven thousand, nine hundred thirty-nine".