65666326643 has 4 divisors (see below), whose sum is σ = 67267944408. Its totient is φ = 64064708880.

The previous prime is 65666326603. The next prime is 65666326651. The reversal of 65666326643 is 34662366656.

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

It is a cyclic number.

It is not a de Polignac number, because 65666326643 - 2²⁰ = 65665278067 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (65666326603) 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, 800808821 + ... + 800808902.

It is an arithmetic number, because the mean of its divisors is an integer number (16816986102).

Almost surely, 2^65666326643 is an apocalyptic number.

65666326643 is a deficient number, since it is larger than the sum of its proper divisors (1601617765).

65666326643 is a wasteful number, since it uses less digits than its factorization.

65666326643 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1601617764.

The product of its digits is 16796160, while the sum is 53.

The spelling of 65666326643 in words is "sixty-five billion, six hundred sixty-six million, three hundred twenty-six thousand, six hundred forty-three".