218480640 has 240 divisors, whose sum is σ = 805281792. Its totient is φ = 49545216.

The previous prime is 218480629. The next prime is 218480659. The reversal of 218480640 is 46084812.

It is a tau number, because it is divible by the number of its divisors (240).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1720257 + ... + 1720383.

Almost surely, 2^218480640 is an apocalyptic number.

218480640 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 218480640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (402640896).

218480640 is an abundant number, since it is smaller than the sum of its proper divisors (586801152).

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

218480640 is an equidigital number, since it uses as much as digits as its factorization.

218480640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 170 (or 144 counting only the distinct ones).

The product of its (nonzero) digits is 12288, while the sum is 33.

The square root of 218480640 is about 14781.0906228194. The cubic root of 218480640 is about 602.2881517324.

The spelling of 218480640 in words is "two hundred eighteen million, four hundred eighty thousand, six hundred forty".