218261220 has 48 divisors (see below), whose sum is σ = 613448640. Its totient is φ = 57982336.

The previous prime is 218261207. The next prime is 218261231. The reversal of 218261220 is 22162812.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 9379 + ... + 22901.

It is an arithmetic number, because the mean of its divisors is an integer number (12780180).

Almost surely, 2^218261220 is an apocalyptic number.

218261220 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

218261220 is an abundant number, since it is smaller than the sum of its proper divisors (395187420).

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

218261220 is a wasteful number, since it uses less digits than its factorization.

218261220 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13804 (or 13802 counting only the distinct ones).

The product of its (nonzero) digits is 768, while the sum is 24.

The square root of 218261220 is about 14773.6664372795. Note that the first 3 decimals coincide. The cubic root of 218261220 is about 602.0864582983.

The spelling of 218261220 in words is "two hundred eighteen million, two hundred sixty-one thousand, two hundred twenty".