218561280 has 288 divisors, whose sum is σ = 819431424. Its totient is φ = 48611328.

The previous prime is 218561269. The next prime is 218561297. The reversal of 218561280 is 82165812.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 1263274 + ... + 1263446.

It is an arithmetic number, because the mean of its divisors is an integer number (2845248).

Almost surely, 2^218561280 is an apocalyptic number.

218561280 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 218561280, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (409715712).

218561280 is an abundant number, since it is smaller than the sum of its proper divisors (600870144).

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

218561280 is a wasteful number, since it uses less digits than its factorization.

218561280 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 251 (or 237 counting only the distinct ones).

The product of its (nonzero) digits is 7680, while the sum is 33.

The square root of 218561280 is about 14783.8181807001. The cubic root of 218561280 is about 602.3622430300.

The spelling of 218561280 in words is "two hundred eighteen million, five hundred sixty-one thousand, two hundred eighty".