66731620816328 has 64 divisors (see below), whose sum is σ = 142685368560000. Its totient is φ = 28984939656192.

The previous prime is 66731620816261. The next prime is 66731620816331. The reversal of 66731620816328 is 82361802613766.

66731620816328 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a super-2 number, since 2×66731620816328² (a number of 28 digits) contains 22 as substring.

It is an unprimeable number.

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 15 ways as a sum of consecutive naturals, for example, 18497843 + ... + 21809021.

It is an arithmetic number, because the mean of its divisors is an integer number (2229458883750).

Almost surely, 2^{66731620816328} is an apocalyptic number.

66731620816328 is a gapful number since it is divisible by the number (68) formed by its first and last digit.

It is an amenable number.

66731620816328 is an abundant number, since it is smaller than the sum of its proper divisors (75953747743672).

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

66731620816328 is a wasteful number, since it uses less digits than its factorization.

66731620816328 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3322614 (or 3322610 counting only the distinct ones).

The product of its (nonzero) digits is 20901888, while the sum is 59.

The spelling of 66731620816328 in words is "sixty-six trillion, seven hundred thirty-one billion, six hundred twenty million, eight hundred sixteen thousand, three hundred twenty-eight".