66106660 has 48 divisors (see below), whose sum is σ = 144471600. Its totient is φ = 25378304.

The previous prime is 66106639. The next prime is 66106697. The reversal of 66106660 is 6660166.

66106660 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 8 ways, for example, as 399424 + 65707236 = 632^2 + 8106^2 .

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, 169746 + ... + 170134.

It is an arithmetic number, because the mean of its divisors is an integer number (3009825).

Almost surely, 2^66106660 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 66106660, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (72235800).

66106660 is an abundant number, since it is smaller than the sum of its proper divisors (78364940).

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

66106660 is a wasteful number, since it uses less digits than its factorization.

66106660 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 720 (or 718 counting only the distinct ones).

The product of its (nonzero) digits is 7776, while the sum is 31.

The square root of 66106660 is about 8130.6002238457. The cubic root of 66106660 is about 404.3415811905.

It can be divided in two parts, 66106 and 660, that added together give a palindrome (66766).

The spelling of 66106660 in words is "sixty-six million, one hundred six thousand, six hundred sixty".