666824400 has 300 divisors, whose sum is σ = 2612136384. Its totient is φ = 161568000.

The previous prime is 666824383. The next prime is 666824419. The reversal of 666824400 is 4428666.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (300).

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent 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 59 ways as a sum of consecutive naturals, for example, 355465 + ... + 357335.

Almost surely, 2^666824400 is an apocalyptic number.

666824400 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 666824400, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1306068192).

666824400 is an abundant number, since it is smaller than the sum of its proper divisors (1945311984).

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

666824400 is a wasteful number, since it uses less digits than its factorization.

666824400 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1912 (or 1892 counting only the distinct ones).

The product of its (nonzero) digits is 55296, while the sum is 36.

The square root of 666824400 is about 25822.9432869299. The cubic root of 666824400 is about 873.6493556827.

The spelling of 666824400 in words is "six hundred sixty-six million, eight hundred twenty-four thousand, four hundred".