218545820 has 24 divisors (see below), whose sum is σ = 463494528. Its totient is φ = 86552000.

The previous prime is 218545813. The next prime is 218545843. The reversal of 218545820 is 28545812.

It is a happy number.

218545820 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

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, 52076 + ... + 56115.

It is an arithmetic number, because the mean of its divisors is an integer number (19312272).

Almost surely, 2^218545820 is an apocalyptic number.

218545820 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

218545820 is an abundant number, since it is smaller than the sum of its proper divisors (244948708).

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

218545820 is a wasteful number, since it uses less digits than its factorization.

218545820 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 108301 (or 108299 counting only the distinct ones).

The product of its (nonzero) digits is 25600, while the sum is 35.

The square root of 218545820 is about 14783.2953024689. The cubic root of 218545820 is about 602.3480399350.

The spelling of 218545820 in words is "two hundred eighteen million, five hundred forty-five thousand, eight hundred twenty".