216810 has 64 divisors (see below), whose sum is σ = 639360. Its totient is φ = 51840.

The previous prime is 216803. The next prime is 216829. The reversal of 216810 is 18612.

It is a super-2 number, since 2×216810² = 94013152200, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (18).

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 216810.

It is an unprimeable number.

216810 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

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 31 ways as a sum of consecutive naturals, for example, 2934 + ... + 3006.

It is an arithmetic number, because the mean of its divisors is an integer number (9990).

2²¹⁶⁸¹⁰ is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 216810, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (319680).

216810 is an abundant number, since it is smaller than the sum of its proper divisors (422550).

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

216810 is a wasteful number, since it uses less digits than its factorization.

216810 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 100 (or 94 counting only the distinct ones).

The product of its (nonzero) digits is 96, while the sum is 18.

The square root of 216810 is about 465.6286073686. The cubic root of 216810 is about 60.0749064448.

The spelling of 216810 in words is "two hundred sixteen thousand, eight hundred ten".