66666666666644 has 48 divisors (see below), whose sum is σ = 127802327216256. Its totient is φ = 30177017472000.

The previous prime is 66666666666641. The next prime is 66666666666647. The reversal of 66666666666644 is 44666666666666.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (66666666666641) and next prime (66666666666647).

It is a nialpdrome in base 10.

It is a zygodrome in base 10.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66666666666641) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 31384784 + ... + 33441560.

It is an arithmetic number, because the mean of its divisors is an integer number (2662548483672).

Almost surely, 2^{66666666666644} is an apocalyptic number.

It is an amenable number.

66666666666644 is a deficient number, since it is larger than the sum of its proper divisors (61135660549612).

66666666666644 is a wasteful number, since it uses less digits than its factorization.

66666666666644 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2059856 (or 2059854 counting only the distinct ones).

The product of its digits is 34828517376, while the sum is 80.

The spelling of 66666666666644 in words is "sixty-six trillion, six hundred sixty-six billion, six hundred sixty-six million, six hundred sixty-six thousand, six hundred forty-four".