218544240 has 80 divisors (see below), whose sum is σ = 679197600. Its totient is φ = 58131456.

The previous prime is 218544211. The next prime is 218544247. The reversal of 218544240 is 42445812.

It is a tau number, because it is divible by the number of its divisors (80).

It is a Harshad number since it is a multiple of its sum of digits (30).

It is a junction number, because it is equal to n+sod(n) for n = 218544198 and 218544207.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (218544247) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 121266 + ... + 123054.

It is an arithmetic number, because the mean of its divisors is an integer number (8489970).

Almost surely, 2^218544240 is an apocalyptic number.

218544240 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 218544240, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (339598800).

218544240 is an abundant number, since it is smaller than the sum of its proper divisors (460653360).

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

218544240 is a wasteful number, since it uses less digits than its factorization.

218544240 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2314 (or 2308 counting only the distinct ones).

The product of its (nonzero) digits is 10240, while the sum is 30.

The square root of 218544240 is about 14783.2418636779. The cubic root of 218544240 is about 602.3465883520.

The spelling of 218544240 in words is "two hundred eighteen million, five hundred forty-four thousand, two hundred forty".