66617157727 has 4 divisors (see below), whose sum is σ = 66915889600. Its totient is φ = 66318425856.

The previous prime is 66617157721. The next prime is 66617157767. The reversal of 66617157727 is 72775171666.

66617157727 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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 66617157727 - 2⁷ = 66617157599 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 (66617157721) 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, 149365602 + ... + 149366047.

It is an arithmetic number, because the mean of its divisors is an integer number (16728972400).

Almost surely, 2^66617157727 is an apocalyptic number.

66617157727 is a deficient number, since it is larger than the sum of its proper divisors (298731873).

66617157727 is a wasteful number, since it uses less digits than its factorization.

66617157727 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 298731872.

The product of its digits is 5186160, while the sum is 55.

The spelling of 66617157727 in words is "sixty-six billion, six hundred seventeen million, one hundred fifty-seven thousand, seven hundred twenty-seven".