218712 has 32 divisors (see below), whose sum is σ = 589680. Its totient is φ = 67200.

The previous prime is 218711. The next prime is 218717. The reversal of 218712 is 217812.

218712 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a Smith number, since the sum of its digits (21) coincides with the sum of the digits of its prime factors.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (218711) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 39 + ... + 662.

2²¹⁸⁷¹² 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 218712, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (294840).

218712 is an abundant number, since it is smaller than the sum of its proper divisors (370968).

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

218712 is a wasteful number, since it uses less digits than its factorization.

218712 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 723 (or 719 counting only the distinct ones).

The product of its digits is 224, while the sum is 21.

The square root of 218712 is about 467.6665478736. Note that the first 3 decimals coincide. The cubic root of 218712 is about 60.2500674345.

Subtracting from 218712 its reverse (217812), we obtain a square (900 = 30²).

It can be divided in two parts, 2187 and 12, that multiplied together give a square (26244 = 162²).

The spelling of 218712 in words is "two hundred eighteen thousand, seven hundred twelve".