66644666 has 16 divisors (see below), whose sum is σ = 114795360. Its totient is φ = 28698480.

The previous prime is 66644663. The next prime is 66644687.

66644666 is nontrivially palindromic in base 10.

It is a zygodrome in base 10.

It is not an unprimeable number, because it can be changed into a prime (66644663) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 79301 + ... + 80136.

It is an arithmetic number, because the mean of its divisors is an integer number (7174710).

Almost surely, 2^66644666 is an apocalyptic number.

66644666 is a deficient number, since it is larger than the sum of its proper divisors (48150694).

66644666 is a wasteful number, since it uses less digits than its factorization.

66644666 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 159469.

The product of its digits is 746496, while the sum is 44.

The square root of 66644666 is about 8163.6184379232. The cubic root of 66644666 is about 405.4355239645.

It can be divided in two parts, 6 and 6644666, that added together give a cube (6644672 = 188³).

The spelling of 66644666 in words is "sixty-six million, six hundred forty-four thousand, six hundred sixty-six".