66539177879 has 4 divisors (see below), whose sum is σ = 70453247184. Its totient is φ = 62625108576.

The previous prime is 66539177833. The next prime is 66539177909. The reversal of 66539177879 is 97877193566.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 97877193566 = 2 ⋅48938596783.

It is a cyclic number.

It is not a de Polignac number, because 66539177879 - 2⁸ = 66539177623 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 (66539177179) 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, 1957034627 + ... + 1957034660.

It is an arithmetic number, because the mean of its divisors is an integer number (17613311796).

Almost surely, 2^66539177879 is an apocalyptic number.

66539177879 is a deficient number, since it is larger than the sum of its proper divisors (3914069305).

66539177879 is a wasteful number, since it uses less digits than its factorization.

66539177879 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3914069304.

The product of its digits is 120022560, while the sum is 68.

The spelling of 66539177879 in words is "sixty-six billion, five hundred thirty-nine million, one hundred seventy-seven thousand, eight hundred seventy-nine".