66728385826 has 16 divisors (see below), whose sum is σ = 100893282048. Its totient is φ = 33098349600.

The previous prime is 66728385797. The next prime is 66728385859. The reversal of 66728385826 is 62858382766.

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 7 ways as a sum of consecutive naturals, for example, 137910 + ... + 390481.

It is an arithmetic number, because the mean of its divisors is an integer number (6305830128).

Almost surely, 2^66728385826 is an apocalyptic number.

66728385826 is a deficient number, since it is larger than the sum of its proper divisors (34164896222).

66728385826 is a wasteful number, since it uses less digits than its factorization.

66728385826 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 528897.

The product of its digits is 46448640, while the sum is 61.

The spelling of 66728385826 in words is "sixty-six billion, seven hundred twenty-eight million, three hundred eighty-five thousand, eight hundred twenty-six".