666066666646 has 4 divisors (see below), whose sum is σ = 999099999972. Its totient is φ = 333033333322.

The previous prime is 666066666619. The next prime is 666066666667. The reversal of 666066666646 is 646666660666.

It is a happy number.

It is a semiprime because it is the product of two primes.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 166516666660 + ... + 166516666663.

It is an arithmetic number, because the mean of its divisors is an integer number (249774999993).

Almost surely, 2^666066666646 is an apocalyptic number.

666066666646 is a deficient number, since it is larger than the sum of its proper divisors (333033333326).

666066666646 is a wasteful number, since it uses less digits than its factorization.

666066666646 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 333033333325.

The product of its (nonzero) digits is 241864704, while the sum is 64.

The spelling of 666066666646 in words is "six hundred sixty-six billion, sixty-six million, six hundred sixty-six thousand, six hundred forty-six".