216939 has 4 divisors (see below), whose sum is σ = 289256. Its totient is φ = 144624.

The previous prime is 216919. The next prime is 216947. The reversal of 216939 is 939612.

It is a semiprime because it is the product of two primes.

It is not a de Polignac number, because 216939 - 2¹¹ = 214891 is a prime.

It is a D-number.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (216919) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 36154 + ... + 36159.

It is an arithmetic number, because the mean of its divisors is an integer number (72314).

2²¹⁶⁹³⁹ is an apocalyptic number.

216939 is a deficient number, since it is larger than the sum of its proper divisors (72317).

216939 is an equidigital number, since it uses as much as digits as its factorization.

216939 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 72316.

The product of its digits is 2916, while the sum is 30.

The square root of 216939 is about 465.7671091866. The cubic root of 216939 is about 60.0868187589.

The spelling of 216939 in words is "two hundred sixteen thousand, nine hundred thirty-nine".