216539 has 4 divisors (see below), whose sum is σ = 219360. Its totient is φ = 213720.

The previous prime is 216523. The next prime is 216551. The reversal of 216539 is 935612.

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

It is a cyclic number.

It is not a de Polignac number, because 216539 - 2⁴ = 216523 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (216509) 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, 1292 + ... + 1449.

It is an arithmetic number, because the mean of its divisors is an integer number (54840).

2²¹⁶⁵³⁹ is an apocalyptic number.

216539 is a deficient number, since it is larger than the sum of its proper divisors (2821).

216539 is an equidigital number, since it uses as much as digits as its factorization.

216539 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2820.

The product of its digits is 1620, while the sum is 26.

The square root of 216539 is about 465.3375119201. The cubic root of 216539 is about 60.0498659524.

The spelling of 216539 in words is "two hundred sixteen thousand, five hundred thirty-nine".