66206666765 has 16 divisors (see below), whose sum is σ = 80451911232. Its totient is φ = 52299287424.

The previous prime is 66206666759. The next prime is 66206666807. The reversal of 66206666765 is 56766660266.

It is a cyclic number.

It is not a de Polignac number, because 66206666765 - 2⁸ = 66206666509 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 66206666765.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 37304 + ... + 365793.

It is an arithmetic number, because the mean of its divisors is an integer number (5028244452).

Almost surely, 2^66206666765 is an apocalyptic number.

It is an amenable number.

66206666765 is a deficient number, since it is larger than the sum of its proper divisors (14245244467).

66206666765 is a wasteful number, since it uses less digits than its factorization.

66206666765 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 403516.

The product of its (nonzero) digits is 19595520, while the sum is 56.

The spelling of 66206666765 in words is "sixty-six billion, two hundred six million, six hundred sixty-six thousand, seven hundred sixty-five".