666444658176 has 320 divisors, whose sum is σ = 2163082268160. Its totient is φ = 200918753280.

The previous prime is 666444658157. The next prime is 666444658181. The reversal of 666444658176 is 671856444666.

It is a happy number.

It is a super-2 number, since 2×666444658176² (a number of 24 digits) contains 22 as substring.

It is a Smith number, since the sum of its digits (63) coincides with the sum of the digits of its prime factors.

It is a congruent 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 31 ways as a sum of consecutive naturals, for example, 29945485 + ... + 29967731.

It is an arithmetic number, because the mean of its divisors is an integer number (6759632088).

Almost surely, 2^666444658176 is an apocalyptic number.

666444658176 is a gapful number since it is divisible by the number (66) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 666444658176, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1081541134080).

666444658176 is an abundant number, since it is smaller than the sum of its proper divisors (1496637609984).

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

666444658176 is a wasteful number, since it uses less digits than its factorization.

666444658176 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 22482 (or 22460 counting only the distinct ones).

The product of its digits is 139345920, while the sum is 63.

The spelling of 666444658176 in words is "six hundred sixty-six billion, four hundred forty-four million, six hundred fifty-eight thousand, one hundred seventy-six".