666594821328 has 120 divisors (see below), whose sum is σ = 1801520841120. Its totient is φ = 212377186560.

The previous prime is 666594821257. The next prime is 666594821339. The reversal of 666594821328 is 823128495666.

It is a happy number.

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 23 ways as a sum of consecutive naturals, for example, 36275983 + ... + 36294353.

It is an arithmetic number, because the mean of its divisors is an integer number (15012673676).

Almost surely, 2^666594821328 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 666594821328, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (900760420560).

666594821328 is an abundant number, since it is smaller than the sum of its proper divisors (1134926019792).

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

666594821328 is a wasteful number, since it uses less digits than its factorization.

666594821328 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 19857 (or 19828 counting only the distinct ones).

The product of its digits is 29859840, while the sum is 60.

The spelling of 666594821328 in words is "six hundred sixty-six billion, five hundred ninety-four million, eight hundred twenty-one thousand, three hundred twenty-eight".