216986 has 16 divisors (see below), whose sum is σ = 406080. Its totient is φ = 84480.

The previous prime is 216973. The next prime is 216991. The reversal of 216986 is 689612.

216986 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It is a plaindrome in base 15.

It is an unprimeable number.

216986 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 7 ways as a sum of consecutive naturals, for example, 551 + ... + 858.

It is an arithmetic number, because the mean of its divisors is an integer number (25380).

2²¹⁶⁹⁸⁶ is an apocalyptic number.

216986 is a deficient number, since it is larger than the sum of its proper divisors (189094).

216986 is a wasteful number, since it uses less digits than its factorization.

216986 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1429.

The product of its digits is 5184, while the sum is 32.

The square root of 216986 is about 465.8175608540. The cubic root of 216986 is about 60.0911577306.

It can be divided in two parts, 21 and 6986, that added together give a palindrome (7007).

The spelling of 216986 in words is "two hundred sixteen thousand, nine hundred eighty-six".