216243 has 8 divisors (see below), whose sum is σ = 320400. Its totient is φ = 144144.

The previous prime is 216233. The next prime is 216259. The reversal of 216243 is 342612.

It is a happy number.

It is not a de Polignac number, because 216243 - 2⁵ = 216211 is a prime.

It is a super-2 number, since 2×216243² = 93522070098, which contains 22 as substring.

216243 is a modest number, since divided by 243 gives 216 as remainder.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 216243.

It is not an unprimeable number, because it can be changed into a prime (216233) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3978 + ... + 4031.

It is an arithmetic number, because the mean of its divisors is an integer number (40050).

2²¹⁶²⁴³ is an apocalyptic number.

216243 is a deficient number, since it is larger than the sum of its proper divisors (104157).

216243 is an equidigital number, since it uses as much as digits as its factorization.

216243 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8018 (or 8012 counting only the distinct ones).

The product of its digits is 288, while the sum is 18.

The square root of 216243 is about 465.0193544359. The cubic root of 216243 is about 60.0224915678.

Subtracting from 216243 its sum of digits (18), we obtain a square (216225 = 465²).

Adding to 216243 its reverse (342612), we get a palindrome (558855).

The spelling of 216243 in words is "two hundred sixteen thousand, two hundred forty-three".