666755812800 has 1008 divisors, whose sum is σ = 3110167008000. Its totient is φ = 131250585600.

The previous prime is 666755812787. The next prime is 666755812813. The reversal of 666755812800 is 8218557666.

It is an interprime number because it is at equal distance from previous prime (666755812787) and next prime (666755812813).

It is a tau number, because it is divible by the number of its divisors (1008).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 143 ways as a sum of consecutive naturals, for example, 21051376 + ... + 21083024.

Almost surely, 2^666755812800 is an apocalyptic number.

666755812800 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 666755812800, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1555083504000).

666755812800 is an abundant number, since it is smaller than the sum of its proper divisors (2443411195200).

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

666755812800 is a wasteful number, since it uses less digits than its factorization.

666755812800 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 31714 (or 31696 counting only the distinct ones).

The product of its (nonzero) digits is 4838400, while the sum is 54.

The spelling of 666755812800 in words is "six hundred sixty-six billion, seven hundred fifty-five million, eight hundred twelve thousand, eight hundred".