213816 has 32 divisors (see below), whose sum is σ = 547200. Its totient is φ = 69600.

The previous prime is 213799. The next prime is 213821. The reversal of 213816 is 618312.

213816 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It is a nude number because it is divisible by every one of its digits.

It is a junction number, because it is equal to n+sod(n) for n = 213792 and 213801.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1341 + ... + 1491.

It is an arithmetic number, because the mean of its divisors is an integer number (17100).

2²¹³⁸¹⁶ is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 213816, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (273600).

213816 is an abundant number, since it is smaller than the sum of its proper divisors (333384).

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

213816 is a wasteful number, since it uses less digits than its factorization.

213816 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 219 (or 215 counting only the distinct ones).

The product of its digits is 288, while the sum is 21.

The square root of 213816 is about 462.4024221390. The cubic root of 213816 is about 59.7970923595.

Subtracting 213816 from its reverse (618312), we obtain a square (404496 = 636²).

The spelling of 213816 in words is "two hundred thirteen thousand, eight hundred sixteen".