66138028871 has 4 divisors (see below), whose sum is σ = 66167412744. Its totient is φ = 66108645000.

The previous prime is 66138028829. The next prime is 66138028889. The reversal of 66138028871 is 17882083166.

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 66138028871 - 2³⁰ = 65064287047 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 (66138028771) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 14688560 + ... + 14693061.

It is an arithmetic number, because the mean of its divisors is an integer number (16541853186).

Almost surely, 2^66138028871 is an apocalyptic number.

66138028871 is a deficient number, since it is larger than the sum of its proper divisors (29383873).

66138028871 is a wasteful number, since it uses less digits than its factorization.

66138028871 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 29383872.

The product of its (nonzero) digits is 774144, while the sum is 50.

The spelling of 66138028871 in words is "sixty-six billion, one hundred thirty-eight million, twenty-eight thousand, eight hundred seventy-one".