666444800 has 132 divisors (see below), whose sum is σ = 1888480320. Its totient is φ = 228433920.

The previous prime is 666444787. The next prime is 666444833. The reversal of 666444800 is 8444666.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 177341 + ... + 181059.

Almost surely, 2^666444800 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 666444800, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (944240160).

666444800 is an abundant number, since it is smaller than the sum of its proper divisors (1222035520).

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

666444800 is a wasteful number, since it uses less digits than its factorization.

666444800 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3756 (or 3733 counting only the distinct ones).

The product of its (nonzero) digits is 110592, while the sum is 38.

The square root of 666444800 is about 25815.5921876683. The cubic root of 666444800 is about 873.4835447910.

The spelling of 666444800 in words is "six hundred sixty-six million, four hundred forty-four thousand, eight hundred".