66646064666 has 8 divisors (see below), whose sum is σ = 105230628480. Its totient is φ = 31569188508.

The previous prime is 66646064663. The next prime is 66646064677.

It is a happy number.

66646064666 is nontrivially palindromic in base 10.

66646064666 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not an unprimeable number, because it can be changed into a prime (66646064663) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 876921866 + ... + 876921941.

It is an arithmetic number, because the mean of its divisors is an integer number (13153828560).

Almost surely, 2^66646064666 is an apocalyptic number.

66646064666 is a deficient number, since it is larger than the sum of its proper divisors (38584563814).

66646064666 is a wasteful number, since it uses less digits than its factorization.

66646064666 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1753843828.

The product of its (nonzero) digits is 26873856, while the sum is 56.

The spelling of 66646064666 in words is "sixty-six billion, six hundred forty-six million, sixty-four thousand, six hundred sixty-six".