216287 has 4 divisors (see below), whose sum is σ = 223296. Its totient is φ = 209280.

The previous prime is 216263. The next prime is 216289. The reversal of 216287 is 782612.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-216287 is a prime.

It is a Duffinian number.

It is a plaindrome in base 16.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (216289) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3458 + ... + 3519.

It is an arithmetic number, because the mean of its divisors is an integer number (55824).

2²¹⁶²⁸⁷ is an apocalyptic number.

216287 is a deficient number, since it is larger than the sum of its proper divisors (7009).

216287 is an equidigital number, since it uses as much as digits as its factorization.

216287 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7008.

The product of its digits is 1344, while the sum is 26.

The square root of 216287 is about 465.0666618884. The cubic root of 216287 is about 60.0265623131.

Adding to 216287 its reverse (782612), we get a palindrome (998899).

The spelling of 216287 in words is "two hundred sixteen thousand, two hundred eighty-seven".