643312800 has 576 divisors, whose sum is σ = 2624832000. Its totient is φ = 150958080.

The previous prime is 643312777. The next prime is 643312801. The reversal of 643312800 is 8213346.

It is a happy number.

643312800 is a `hidden beast` number, since 643 + 3 + 12 + 8 + 0 + 0 = 666.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is not an unprimeable number, because it can be changed into a prime (643312801) by changing a digit.

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 95 ways as a sum of consecutive naturals, for example, 8143161 + ... + 8143239.

It is an arithmetic number, because the mean of its divisors is an integer number (4557000).

Almost surely, 2^643312800 is an apocalyptic number.

643312800 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 643312800, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1312416000).

643312800 is an abundant number, since it is smaller than the sum of its proper divisors (1981519200).

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

643312800 is a wasteful number, since it uses less digits than its factorization.

643312800 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 150 (or 131 counting only the distinct ones).

The product of its (nonzero) digits is 3456, while the sum is 27.

The square root of 643312800 is about 25363.6117301933. The cubic root of 643312800 is about 863.2582368189.

The spelling of 643312800 in words is "six hundred forty-three million, three hundred twelve thousand, eight hundred".