216993 has 8 divisors (see below), whose sum is σ = 330688. Its totient is φ = 123984.

The previous prime is 216991. The next prime is 217001. The reversal of 216993 is 399612.

Added to its reverse (399612) it gives a triangular number (616605 = T₁₁₁₀).

216993 is digitally balanced in base 7, because in such base it contains all the possibile digits an equal number of times.

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

It is not a de Polignac number, because 216993 - 2¹ = 216991 is a prime.

It is a Duffinian number.

216993 is strictly pandigital in base 7.

It is a self number, because there is not a number n which added to its sum of digits gives 216993.

It is not an unprimeable number, because it can be changed into a prime (216991) 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, 5146 + ... + 5187.

It is an arithmetic number, because the mean of its divisors is an integer number (41336).

2²¹⁶⁹⁹³ is an apocalyptic number.

It is an amenable number.

216993 is a deficient number, since it is larger than the sum of its proper divisors (113695).

216993 is a wasteful number, since it uses less digits than its factorization.

216993 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10343.

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

The square root of 216993 is about 465.8250744647. The cubic root of 216993 is about 60.0918039068.

Adding to 216993 its reverse (399612), we get a triangular number (616605 = T₁₁₁₀).

The spelling of 216993 in words is "two hundred sixteen thousand, nine hundred ninety-three".