66155265791 has 8 divisors (see below), whose sum is σ = 70049014560. Its totient is φ = 62261768448.

The previous prime is 66155265751. The next prime is 66155265811. The reversal of 66155265791 is 19756255166.

It is a happy number.

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

It is a cyclic number.

It is not a de Polignac number, because 66155265791 - 2¹⁸ = 66155003647 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66155265721) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 903275 + ... + 973763.

It is an arithmetic number, because the mean of its divisors is an integer number (8756126820).

Almost surely, 2^66155265791 is an apocalyptic number.

66155265791 is a deficient number, since it is larger than the sum of its proper divisors (3893748769).

66155265791 is a wasteful number, since it uses less digits than its factorization.

66155265791 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 125713.

The product of its digits is 3402000, while the sum is 53.

The spelling of 66155265791 in words is "sixty-six billion, one hundred fifty-five million, two hundred sixty-five thousand, seven hundred ninety-one".