668858561280 has 1728 divisors, whose sum is σ = 3013264800000. Its totient is φ = 135952072704.

The previous prime is 668858561263. The next prime is 668858561291. The reversal of 668858561280 is 82165858866.

668858561280 is a `hidden beast` number, since 6 + 6 + 8 + 8 + 5 + 8 + 5 + 612 + 8 + 0 = 666.

It is a Harshad number since it is a multiple of its sum of digits (63).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 191 ways as a sum of consecutive naturals, for example, 1489662496 + ... + 1489662944.

It is an arithmetic number, because the mean of its divisors is an integer number (1743787500).

Almost surely, 2^668858561280 is an apocalyptic number.

668858561280 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 668858561280, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1506632400000).

668858561280 is an abundant number, since it is smaller than the sum of its proper divisors (2344406238720).

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

668858561280 is a wasteful number, since it uses less digits than its factorization.

668858561280 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 539 (or 508 counting only the distinct ones).

The product of its (nonzero) digits is 44236800, while the sum is 63.

The spelling of 668858561280 in words is "six hundred sixty-eight billion, eight hundred fifty-eight million, five hundred sixty-one thousand, two hundred eighty".