666386816928 has 384 divisors, whose sum is σ = 2059468185600. Its totient is φ = 184757760000.

The previous prime is 666386816869. The next prime is 666386816999. The reversal of 666386816928 is 829618683666.

It is a super-4 number, since 4×666386816928⁴ (a number of 48 digits) contains 4444 as substring.

Its product of digits (214990848) is a multiple of the sum of its prime factors (972).

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 1231768338 + ... + 1231768878.

It is an arithmetic number, because the mean of its divisors is an integer number (5363198400).

Almost surely, 2^666386816928 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 666386816928, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1029734092800).

666386816928 is an abundant number, since it is smaller than the sum of its proper divisors (1393081368672).

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

666386816928 is a wasteful number, since it uses less digits than its factorization.

666386816928 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 972 (or 964 counting only the distinct ones).

The product of its digits is 214990848, while the sum is 69.

The spelling of 666386816928 in words is "six hundred sixty-six billion, three hundred eighty-six million, eight hundred sixteen thousand, nine hundred twenty-eight".