218680520 has 48 divisors (see below), whose sum is σ = 522704340. Its totient is φ = 82322432.

The previous prime is 218680507. The next prime is 218680523. The reversal of 218680520 is 25086812.

It can be written as a sum of positive squares in 6 ways, for example, as 186213316 + 32467204 = 13646^2 + 5698^2 .

It is not an unprimeable number, because it can be changed into a prime (218680523) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 2102 + ... + 21018.

Almost surely, 2^218680520 is an apocalyptic number.

218680520 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 218680520, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (261352170).

218680520 is an abundant number, since it is smaller than the sum of its proper divisors (304023820).

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

218680520 is a wasteful number, since it uses less digits than its factorization.

218680520 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 18962 (or 18941 counting only the distinct ones).

The product of its (nonzero) digits is 7680, while the sum is 32.

The square root of 218680520 is about 14787.8504185023. The cubic root of 218680520 is about 602.4717662659.

The spelling of 218680520 in words is "two hundred eighteen million, six hundred eighty thousand, five hundred twenty".