216444 has 24 divisors (see below), whose sum is σ = 535248. Its totient is φ = 67840.

The previous prime is 216431. The next prime is 216451. The reversal of 216444 is 444612.

216444 = T₁₅₁ + T₁₅₂ + ... + T₁₆₇.

It is a hoax number, since the sum of its digits (21) coincides with the sum of the digits of its distinct prime factors.

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

216444 is a modest number, since divided by 444 gives 216 as remainder.

It is a nialpdrome in base 12.

It is a self number, because there is not a number n which added to its sum of digits gives 216444.

It is a congruent number.

It is an unprimeable number.

216444 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

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 7 ways as a sum of consecutive naturals, for example, 327 + ... + 734.

It is an arithmetic number, because the mean of its divisors is an integer number (22302).

2²¹⁶⁴⁴⁴ is an apocalyptic number.

It is an amenable number.

216444 is an abundant number, since it is smaller than the sum of its proper divisors (318804).

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

216444 is a wasteful number, since it uses less digits than its factorization.

216444 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1085 (or 1083 counting only the distinct ones).

The product of its digits is 768, while the sum is 21.

The square root of 216444 is about 465.2354242746. The cubic root of 216444 is about 60.0410829745.

The spelling of 216444 in words is "two hundred sixteen thousand, four hundred forty-four".