861685 has 8 divisors (see below), whose sum is σ = 1128096. Its totient is φ = 626640.

The previous prime is 861659. The next prime is 861691. The reversal of 861685 is 586168.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 861685 - 2¹³ = 853493 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 861685.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 7779 + ... + 7888.

It is an arithmetic number, because the mean of its divisors is an integer number (141012).

2⁸⁶¹⁶⁸⁵ is an apocalyptic number.

It is an amenable number.

861685 is a deficient number, since it is larger than the sum of its proper divisors (266411).

861685 is a wasteful number, since it uses less digits than its factorization.

861685 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 15683.

The product of its digits is 11520, while the sum is 34.

The square root of 861685 is about 928.2698960970. The cubic root of 861685 is about 95.1589214412.

It can be divided in two parts, 86 and 1685, that added together give a palindrome (1771).

The spelling of 861685 in words is "eight hundred sixty-one thousand, six hundred eighty-five".