216187 has 4 divisors (see below), whose sum is σ = 220320. Its totient is φ = 212056.

The previous prime is 216179. The next prime is 216211. The reversal of 216187 is 781612.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 216187 - 2³ = 216179 is a prime.

It is an alternating number because its digits alternate between even and odd.

It is a Duffinian number.

216187 is a lucky number.

It is a plaindrome in base 14.

It is not an unprimeable number, because it can be changed into a prime (216107) by changing a digit.

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, 1987 + ... + 2092.

It is an arithmetic number, because the mean of its divisors is an integer number (55080).

2²¹⁶¹⁸⁷ is an apocalyptic number.

216187 is a deficient number, since it is larger than the sum of its proper divisors (4133).

216187 is an equidigital number, since it uses as much as digits as its factorization.

216187 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4132.

The product of its digits is 672, while the sum is 25.

The square root of 216187 is about 464.9591379896. The cubic root of 216187 is about 60.0173098205.

Adding to 216187 its reverse (781612), we get a palindrome (997799).

The spelling of 216187 in words is "two hundred sixteen thousand, one hundred eighty-seven".