66138028872 has 64 divisors (see below), whose sum is σ = 174251563200. Its totient is φ = 20861199360.

The previous prime is 66138028829. The next prime is 66138028889. The reversal of 66138028872 is 27882083166.

It is a happy number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 306172 + ... + 475412.

It is an arithmetic number, because the mean of its divisors is an integer number (2722680675).

Almost surely, 2^66138028872 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 66138028872, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (87125781600).

66138028872 is an abundant number, since it is smaller than the sum of its proper divisors (108113534328).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

66138028872 is a wasteful number, since it uses less digits than its factorization.

66138028872 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 170126 (or 170122 counting only the distinct ones).

The product of its (nonzero) digits is 1548288, while the sum is 51.

The spelling of 66138028872 in words is "sixty-six billion, one hundred thirty-eight million, twenty-eight thousand, eight hundred seventy-two".