66814220 has 48 divisors (see below), whose sum is σ = 153770400. Its totient is φ = 24184320.

The previous prime is 66814201. The next prime is 66814229. The reversal of 66814220 is 2241866.

66814220 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not an unprimeable number, because it can be changed into a prime (66814229) by changing a digit.

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, 58616 + ... + 59744.

It is an arithmetic number, because the mean of its divisors is an integer number (3203550).

Almost surely, 2^66814220 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 66814220, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (76885200).

66814220 is an abundant number, since it is smaller than the sum of its proper divisors (86956180).

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

66814220 is a wasteful number, since it uses less digits than its factorization.

66814220 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1418 (or 1416 counting only the distinct ones).

The product of its (nonzero) digits is 4608, while the sum is 29.

The square root of 66814220 is about 8173.9965745038. The cubic root of 66814220 is about 405.7790623327.

It can be divided in two parts, 6681 and 4220, that added together give a palindrome (10901).

The spelling of 66814220 in words is "sixty-six million, eight hundred fourteen thousand, two hundred twenty".