861688 has 16 divisors (see below), whose sum is σ = 1701000. Its totient is φ = 408096.

The previous prime is 861659. The next prime is 861691. The reversal of 861688 is 886168.

It is a congruent number.

It is an unprimeable number.

861688 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2683 + ... + 2986.

2⁸⁶¹⁶⁸⁸ is an apocalyptic number.

It is an amenable number.

861688 is a deficient number, since it is larger than the sum of its proper divisors (839312).

861688 is a wasteful number, since it uses less digits than its factorization.

861688 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5694 (or 5690 counting only the distinct ones).

The product of its digits is 18432, while the sum is 37.

The square root of 861688 is about 928.2715120050. The cubic root of 861688 is about 95.1590318746.

The spelling of 861688 in words is "eight hundred sixty-one thousand, six hundred eighty-eight".