668517543388800 has 4032 divisors, whose sum is σ = 3010347397935360. Its totient is φ = 146028950323200.

The previous prime is 668517543388781. The next prime is 668517543388819. The reversal of 668517543388800 is 8883345715866.

668517543388800 is a `hidden beast` number, since 6 + 68 + 5 + 1 + 75 + 43 + 388 + 80 + 0 = 666.

It is an interprime number because it is at equal distance from previous prime (668517543388781) and next prime (668517543388819).

It is a tau number, because it is divible by the number of its divisors (4032).

It is a Harshad number since it is a multiple of its sum of digits (72).

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 503 ways as a sum of consecutive naturals, for example, 294112424464 + ... + 294112426736.

It is an arithmetic number, because the mean of its divisors is an integer number (746613937980).

Almost surely, 2^{668517543388800} is an apocalyptic number.

668517543388800 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 668517543388800, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1505173698967680).

668517543388800 is an abundant number, since it is smaller than the sum of its proper divisors (2341829854546560).

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

668517543388800 is a wasteful number, since it uses less digits than its factorization.

668517543388800 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2443 (or 2404 counting only the distinct ones).

The product of its (nonzero) digits is 928972800, while the sum is 72.

The spelling of 668517543388800 in words is "six hundred sixty-eight trillion, five hundred seventeen billion, five hundred forty-three million, three hundred eighty-eight thousand, eight hundred".