66127688671 has 4 divisors (see below), whose sum is σ = 72139296744. Its totient is φ = 60116080600.

The previous prime is 66127688639. The next prime is 66127688689. The reversal of 66127688671 is 17688672166.

It is a happy number.

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 66127688671 - 2⁵ = 66127688639 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 (66127688621) 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, 3005804020 + ... + 3005804041.

It is an arithmetic number, because the mean of its divisors is an integer number (18034824186).

Almost surely, 2^66127688671 is an apocalyptic number.

66127688671 is a deficient number, since it is larger than the sum of its proper divisors (6011608073).

66127688671 is a wasteful number, since it uses less digits than its factorization.

66127688671 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6011608072.

The product of its digits is 8128512, while the sum is 58.

It can be divided in two parts, 661276 and 88671, that added together give a palindrome (749947).

The spelling of 66127688671 in words is "sixty-six billion, one hundred twenty-seven million, six hundred eighty-eight thousand, six hundred seventy-one".