861686 has 16 divisors (see below), whose sum is σ = 1502880. Its totient is φ = 362880.

The previous prime is 861659. The next prime is 861691. The reversal of 861686 is 686168.

It is a congruent number.

It is an unprimeable number.

861686 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 350 + ... + 1358.

It is an arithmetic number, because the mean of its divisors is an integer number (93930).

2⁸⁶¹⁶⁸⁶ is an apocalyptic number.

861686 is a deficient number, since it is larger than the sum of its proper divisors (641194).

861686 is a wasteful number, since it uses less digits than its factorization.

861686 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1079.

The product of its digits is 13824, while the sum is 35.

The square root of 861686 is about 928.2704347333. The cubic root of 861686 is about 95.1589582523.

The spelling of 861686 in words is "eight hundred sixty-one thousand, six hundred eighty-six".