688687 has 6 divisors (see below), whose sum is σ = 731888. Its totient is φ = 647904.

The previous prime is 688679. The next prime is 688697. The reversal of 688687 is 786886.

It is a happy number.

It is not a de Polignac number, because 688687 - 2³ = 688679 is a prime.

It is a Duffinian number.

688687 is a lucky number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (688627) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 903 + ... + 1480.

2⁶⁸⁸⁶⁸⁷ is an apocalyptic number.

688687 is a deficient number, since it is larger than the sum of its proper divisors (43201).

688687 is a wasteful number, since it uses less digits than its factorization.

688687 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2417 (or 2400 counting only the distinct ones).

The product of its digits is 129024, while the sum is 43.

The square root of 688687 is about 829.8716768272. The cubic root of 688687 is about 88.3094734022.

The spelling of 688687 in words is "six hundred eighty-eight thousand, six hundred eighty-seven".