218624 has 40 divisors (see below), whose sum is σ = 507408. Its totient is φ = 92160.

The previous prime is 218623. The next prime is 218627. The reversal of 218624 is 426812.

It is a nialpdrome in base 8.

It is a self number, because there is not a number n which added to its sum of digits gives 218624.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (218623) 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, 3554 + ... + 3614.

2²¹⁸⁶²⁴ 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 218624, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (253704).

218624 is an abundant number, since it is smaller than the sum of its proper divisors (288784).

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

218624 is an frugal number, since it uses more digits than its factorization.

218624 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 86 (or 70 counting only the distinct ones).

The product of its digits is 768, while the sum is 23.

The square root of 218624 is about 467.5724542785. The cubic root of 218624 is about 60.2419856996.

The spelling of 218624 in words is "two hundred eighteen thousand, six hundred twenty-four".