66009216 has 128 divisors (see below), whose sum is σ = 215913600. Its totient is φ = 17399808.

The previous prime is 66009187. The next prime is 66009239. The reversal of 66009216 is 61290066.

66009216 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a tau number, because it is divible by the number of its divisors (128).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 34000 + ... + 35888.

It is an arithmetic number, because the mean of its divisors is an integer number (1686825).

Almost surely, 2^66009216 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 66009216, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (107956800).

66009216 is an abundant number, since it is smaller than the sum of its proper divisors (149904384).

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

66009216 is a wasteful number, since it uses less digits than its factorization.

66009216 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1926 (or 1914 counting only the distinct ones).

The product of its (nonzero) digits is 3888, while the sum is 30.

The square root of 66009216 is about 8124.6055904271. The cubic root of 66009216 is about 404.1428113221.

The spelling of 66009216 in words is "sixty-six million, nine thousand, two hundred sixteen".