666066165661 has 16 divisors (see below), whose sum is σ = 750895891200. Its totient is φ = 586207480320.

The previous prime is 666066165649. The next prime is 666066165689. The reversal of 666066165661 is 166561660666.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-666066165661 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (666066162661) 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, 3488436 + ... + 3674413.

It is an arithmetic number, because the mean of its divisors is an integer number (46930993200).

Almost surely, 2^666066165661 is an apocalyptic number.

It is an amenable number.

666066165661 is a deficient number, since it is larger than the sum of its proper divisors (84829725539).

666066165661 is a wasteful number, since it uses less digits than its factorization.

666066165661 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7163196.

The product of its (nonzero) digits is 8398080, while the sum is 55.

The spelling of 666066165661 in words is "six hundred sixty-six billion, sixty-six million, one hundred sixty-five thousand, six hundred sixty-one".