216858 has 16 divisors (see below), whose sum is σ = 443520. Its totient is φ = 70656.

The previous prime is 216851. The next prime is 216859. The reversal of 216858 is 858612.

It is a congruent number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 216858.

It is not an unprimeable number, because it can be changed into a prime (216851) by changing a digit.

216858 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, 103 + ... + 666.

It is an arithmetic number, because the mean of its divisors is an integer number (27720).

2²¹⁶⁸⁵⁸ is an apocalyptic number.

216858 is an abundant number, since it is smaller than the sum of its proper divisors (226662).

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

216858 is a wasteful number, since it uses less digits than its factorization.

216858 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 821.

The product of its digits is 3840, while the sum is 30.

The square root of 216858 is about 465.6801477409. The cubic root of 216858 is about 60.0793394856.

The spelling of 216858 in words is "two hundred sixteen thousand, eight hundred fifty-eight".