668532221280 has 1728 divisors, whose sum is σ = 3066440509440. Its totient is φ = 135461652480.

The previous prime is 668532221221. The next prime is 668532221317. The reversal of 668532221280 is 82122235866.

668532221280 is a `hidden beast` number, since 6 + 6 + 8 + 532 + 22 + 12 + 80 = 666.

It is a Harshad number since it is a multiple of its sum of digits (45).

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 287 ways as a sum of consecutive naturals, for example, 1101370737 + ... + 1101371343.

It is an arithmetic number, because the mean of its divisors is an integer number (1774560480).

Almost surely, 2^668532221280 is an apocalyptic number.

668532221280 is a gapful number since it is divisible by the number (60) 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 668532221280, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1533220254720).

668532221280 is an abundant number, since it is smaller than the sum of its proper divisors (2397908288160).

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

668532221280 is a wasteful number, since it uses less digits than its factorization.

668532221280 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 710 (or 678 counting only the distinct ones).

The product of its (nonzero) digits is 552960, while the sum is 45.

The spelling of 668532221280 in words is "six hundred sixty-eight billion, five hundred thirty-two million, two hundred twenty-one thousand, two hundred eighty".