216441 has 6 divisors (see below), whose sum is σ = 312650. Its totient is φ = 144288.

The previous prime is 216431. The next prime is 216451. The reversal of 216441 is 144612.

216441 is a `hidden beast` number, since 21 + 644 + 1 = 666.

It is an interprime number because it is at equal distance from previous prime (216431) and next prime (216451).

It can be written as a sum of positive squares in only one way, i.e., 184041 + 32400 = 429^2 + 180^2 .

It is not a de Polignac number, because 216441 - 2¹⁰ = 215417 is a prime.

It is a Duffinian number.

216441 is a lucky number.

It is not an unprimeable number, because it can be changed into a prime (216401) 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 5 ways as a sum of consecutive naturals, for example, 12016 + ... + 12033.

2²¹⁶⁴⁴¹ is an apocalyptic number.

It is an amenable number.

216441 is a deficient number, since it is larger than the sum of its proper divisors (96209).

216441 is a wasteful number, since it uses less digits than its factorization.

216441 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 24055 (or 24052 counting only the distinct ones).

The product of its digits is 192, while the sum is 18.

The square root of 216441 is about 465.2322000894. The cubic root of 216441 is about 60.0408055755.

The spelling of 216441 in words is "two hundred sixteen thousand, four hundred forty-one".