218507220 has 240 divisors, whose sum is σ = 748070400. Its totient is φ = 53187840.

The previous prime is 218507213. The next prime is 218507231. The reversal of 218507220 is 22705812.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 79 ways as a sum of consecutive naturals, for example, 954066 + ... + 954294.

It is an arithmetic number, because the mean of its divisors is an integer number (3116960).

Almost surely, 2^218507220 is an apocalyptic number.

218507220 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 218507220, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (374035200).

218507220 is an abundant number, since it is smaller than the sum of its proper divisors (529563180).

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

218507220 is a wasteful number, since it uses less digits than its factorization.

218507220 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 300 (or 289 counting only the distinct ones).

The product of its (nonzero) digits is 2240, while the sum is 27.

The square root of 218507220 is about 14781.9897172201. The cubic root of 218507220 is about 602.3125752083.

The spelling of 218507220 in words is "two hundred eighteen million, five hundred seven thousand, two hundred twenty".