666378820800 has 1512 divisors, whose sum is σ = 3041772814080. Its totient is φ = 134419046400.

The previous prime is 666378820777. The next prime is 666378820843. The reversal of 666378820800 is 8028873666.

It is a happy number.

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 215 ways as a sum of consecutive naturals, for example, 1517946981 + ... + 1517947419.

Almost surely, 2^666378820800 is an apocalyptic number.

666378820800 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 666378820800, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1520886407040).

666378820800 is an abundant number, since it is smaller than the sum of its proper divisors (2375393993280).

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

666378820800 is a wasteful number, since it uses less digits than its factorization.

666378820800 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 559 (or 504 counting only the distinct ones).

The product of its (nonzero) digits is 4644864, while the sum is 54.

The spelling of 666378820800 in words is "six hundred sixty-six billion, three hundred seventy-eight million, eight hundred twenty thousand, eight hundred".