66640004666 has 16 divisors (see below), whose sum is σ = 101156385120. Its totient is φ = 32923482480.

The previous prime is 66640004609. The next prime is 66640004671.

66640004666 is nontrivially palindromic in base 10.

It is a Smith number, since the sum of its digits (44) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is an unprimeable number.

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, 509381 + ... + 626696.

It is an arithmetic number, because the mean of its divisors is an integer number (6322274070).

Almost surely, 2^66640004666 is an apocalyptic number.

66640004666 is a deficient number, since it is larger than the sum of its proper divisors (34516380454).

66640004666 is a wasteful number, since it uses less digits than its factorization.

66640004666 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1136429.

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

It can be divided in two parts, 6664000 and 4666, that added together give a palindrome (6668666).

The spelling of 66640004666 in words is "sixty-six billion, six hundred forty million, four thousand, six hundred sixty-six".