66028128109 has 8 divisors (see below), whose sum is σ = 69211562112. Its totient is φ = 62919598560.

The previous prime is 66028128077. The next prime is 66028128113. The reversal of 66028128109 is 90182182066.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 66028128109 - 2⁵ = 66028128077 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (43).

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66028128139) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 18724309 + ... + 18727834.

It is an arithmetic number, because the mean of its divisors is an integer number (8651445264).

Almost surely, 2^66028128109 is an apocalyptic number.

It is an amenable number.

66028128109 is a deficient number, since it is larger than the sum of its proper divisors (3183434003).

66028128109 is a wasteful number, since it uses less digits than its factorization.

66028128109 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 37452227.

The product of its (nonzero) digits is 82944, while the sum is 43.

The spelling of 66028128109 in words is "sixty-six billion, twenty-eight million, one hundred twenty-eight thousand, one hundred nine".