66305220 has 48 divisors (see below), whose sum is σ = 187474560. Its totient is φ = 17508096.

The previous prime is 66305209. The next prime is 66305237. The reversal of 66305220 is 2250366.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 816 + ... + 11544.

It is an arithmetic number, because the mean of its divisors is an integer number (3905720).

Almost surely, 2^66305220 is an apocalyptic number.

66305220 is a gapful number since it is divisible by the number (60) 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 66305220, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (93737280).

66305220 is an abundant number, since it is smaller than the sum of its proper divisors (121169340).

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

66305220 is a wasteful number, since it uses less digits than its factorization.

66305220 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10844 (or 10842 counting only the distinct ones).

The product of its (nonzero) digits is 2160, while the sum is 24.

The square root of 66305220 is about 8142.8017291348. The cubic root of 66305220 is about 404.7460074868.

Adding to 66305220 its reverse (2250366), we get a palindrome (68555586).

The spelling of 66305220 in words is "sixty-six million, three hundred five thousand, two hundred twenty".