216390 has 16 divisors (see below), whose sum is σ = 519408. Its totient is φ = 57696.

The previous prime is 216379. The next prime is 216397. The reversal of 216390 is 93612.

216390 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a Curzon number.

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.

216390 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3577 + ... + 3636.

It is an arithmetic number, because the mean of its divisors is an integer number (32463).

2²¹⁶³⁹⁰ is an apocalyptic number.

216390 is an abundant number, since it is smaller than the sum of its proper divisors (303018).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

216390 is a wasteful number, since it uses less digits than its factorization.

216390 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7223.

The product of its (nonzero) digits is 324, while the sum is 21.

The square root of 216390 is about 465.1773855208. The cubic root of 216390 is about 60.0360893993.

It can be divided in two parts, 216 and 390, that added together give a palindrome (606).

The spelling of 216390 in words is "two hundred sixteen thousand, three hundred ninety".