66580218 has 80 divisors (see below), whose sum is σ = 159371520. Its totient is φ = 20715264.

The previous prime is 66580207. The next prime is 66580223. The reversal of 66580218 is 81208566.

It is a happy number.

66580218 is a `hidden beast` number, since 66 + 580 + 2 + 18 = 666.

It is a Curzon number.

It is an unprimeable number.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 298455 + ... + 298677.

It is an arithmetic number, because the mean of its divisors is an integer number (1992144).

Almost surely, 2^66580218 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 66580218, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (79685760).

66580218 is an abundant number, since it is smaller than the sum of its proper divisors (92791302).

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

66580218 is a wasteful number, since it uses less digits than its factorization.

66580218 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 353 (or 344 counting only the distinct ones).

The product of its (nonzero) digits is 23040, while the sum is 36.

The square root of 66580218 is about 8159.6702139241. The cubic root of 66580218 is about 405.3047911417.

The spelling of 66580218 in words is "sixty-six million, five hundred eighty thousand, two hundred eighteen".