643420800 has 384 divisors, whose sum is σ = 2572603200. Its totient is φ = 155750400.

The previous prime is 643420781. The next prime is 643420801. The reversal of 643420800 is 8024346.

It is a tau number, because it is divible by the number of its divisors (384).

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 (643420801) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 950062 + ... + 950738.

Almost surely, 2^643420800 is an apocalyptic number.

643420800 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 643420800, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1286301600).

643420800 is an abundant number, since it is smaller than the sum of its proper divisors (1929182400).

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

643420800 is a wasteful number, since it uses less digits than its factorization.

643420800 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 721 (or 698 counting only the distinct ones).

The product of its (nonzero) digits is 4608, while the sum is 27.

The square root of 643420800 is about 25365.7406751705. The cubic root of 643420800 is about 863.3065423362.

The spelling of 643420800 in words is "six hundred forty-three million, four hundred twenty thousand, eight hundred".