243216 has 40 divisors (see below), whose sum is σ = 699360. Its totient is φ = 80928.

The previous prime is 243209. The next prime is 243227. The reversal of 243216 is 612342.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a nude number because it is divisible by every one of its digits.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 243216.

It is an unprimeable number.

243216 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 151 + ... + 713.

It is an arithmetic number, because the mean of its divisors is an integer number (17484).

2²⁴³²¹⁶ is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 243216, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (349680).

243216 is an abundant number, since it is smaller than the sum of its proper divisors (456144).

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

243216 is a wasteful number, since it uses less digits than its factorization.

243216 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 580 (or 568 counting only the distinct ones).

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

The square root of 243216 is about 493.1693421128. The cubic root of 243216 is about 62.4209988498.

Adding to 243216 its reverse (612342), we get a palindrome (855558).

It can be divided in two parts, 24 and 3216, that added together give a triangular number (3240 = T₈₀).

The spelling of 243216 in words is "two hundred forty-three thousand, two hundred sixteen".