216399 has 8 divisors (see below), whose sum is σ = 294192. Its totient is φ = 141440.

The previous prime is 216397. The next prime is 216401. The reversal of 216399 is 993612.

It is an interprime number because it is at equal distance from previous prime (216397) and next prime (216401).

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

It is a cyclic number.

It is not a de Polignac number, because 216399 - 2¹ = 216397 is a prime.

It is a nialpdrome in base 13.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (216397) 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 7 ways as a sum of consecutive naturals, for example, 522 + ... + 839.

It is an arithmetic number, because the mean of its divisors is an integer number (36774).

2²¹⁶³⁹⁹ is an apocalyptic number.

216399 is a deficient number, since it is larger than the sum of its proper divisors (77793).

216399 is a wasteful number, since it uses less digits than its factorization.

216399 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1417.

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

The square root of 216399 is about 465.1870591493. The cubic root of 216399 is about 60.0369217196.

The spelling of 216399 in words is "two hundred sixteen thousand, three hundred ninety-nine".