16686 has 20 divisors (see below), whose sum is σ = 37752. Its totient is φ = 5508.

The previous prime is 16673. The next prime is 16691. The reversal of 16686 is 68661.

It is a Harshad number since it is a multiple of its sum of digits (27).

Its product of digits (1728) is a multiple of the sum of its prime divisors (108).

It is a plaindrome in base 11.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 9 ways as a sum of consecutive naturals, for example, 111 + ... + 213.

2¹⁶⁶⁸⁶ is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 16686, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (18876).

16686 is an abundant number, since it is smaller than the sum of its proper divisors (21066).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

16686 is a wasteful number, since it uses less digits than its factorization.

16686 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 117 (or 108 counting only the distinct ones).

The product of its digits is 1728, while the sum is 27.

The square root of 16686 is about 129.1743008497. The cubic root of 16686 is about 25.5535208070.

It can be divided in two parts, 166 and 86, that added together give a palindrome (252).

The spelling of 16686 in words is "sixteen thousand, six hundred eighty-six".