216281 has 8 divisors (see below), whose sum is σ = 236544. Its totient is φ = 196560.

The previous prime is 216263. The next prime is 216289. The reversal of 216281 is 182612.

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

It is not a de Polignac number, because 216281 - 2⁶ = 216217 is a prime.

It is a super-2 number, since 2×216281² = 93554941922, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (216289) 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, 1586 + ... + 1716.

It is an arithmetic number, because the mean of its divisors is an integer number (29568).

2²¹⁶²⁸¹ is an apocalyptic number.

It is an amenable number.

216281 is a deficient number, since it is larger than the sum of its proper divisors (20263).

216281 is a wasteful number, since it uses less digits than its factorization.

216281 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 271.

The product of its digits is 192, while the sum is 20.

The square root of 216281 is about 465.0602111555. The cubic root of 216281 is about 60.0260072439.

Adding to 216281 its reverse (182612), we get a palindrome (398893).

The spelling of 216281 in words is "two hundred sixteen thousand, two hundred eighty-one".