216438 has 8 divisors (see below), whose sum is σ = 432888. Its totient is φ = 72144.

The previous prime is 216431. The next prime is 216451. The reversal of 216438 is 834612.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

216438 is an admirable number.

It is a Smith number, since the sum of its digits (24) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a congruent number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 216438.

It is not an unprimeable number, because it can be changed into a prime (216431) 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, 18031 + ... + 18042.

It is an arithmetic number, because the mean of its divisors is an integer number (54111).

2²¹⁶⁴³⁸ is an apocalyptic number.

216438 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

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

216438 is a wasteful number, since it uses less digits than its factorization.

216438 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 36078.

The product of its digits is 1152, while the sum is 24.

The square root of 216438 is about 465.2289758818. The cubic root of 216438 is about 60.0405281738.

The spelling of 216438 in words is "two hundred sixteen thousand, four hundred thirty-eight".