6664642666 has 16 divisors (see below), whose sum is σ = 10907353440. Its totient is φ = 3028945680.

The previous prime is 6664642643. The next prime is 6664642669. The reversal of 6664642666 is 6662464666.

It is not an unprimeable number, because it can be changed into a prime (6664642669) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 172285 + ... + 207391.

It is an arithmetic number, because the mean of its divisors is an integer number (681709590).

Almost surely, 2^6664642666 is an apocalyptic number.

6664642666 is a deficient number, since it is larger than the sum of its proper divisors (4242710774).

6664642666 is a wasteful number, since it uses less digits than its factorization.

6664642666 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 43749.

The product of its digits is 8957952, while the sum is 52.

The square root of 6664642666 is about 81637.2627297119. The cubic root of 6664642666 is about 1881.8815727287.

The spelling of 6664642666 in words is "six billion, six hundred sixty-four million, six hundred forty-two thousand, six hundred sixty-six".