643222000 has 40 divisors (see below), whose sum is σ = 1555315632. Its totient is φ = 257288000.

The previous prime is 643221989. The next prime is 643222009. The reversal of 643222000 is 222346.

643222000 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a tau number, because it is divible by the number of its divisors (40).

It is a nialpdrome in base 10.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (643222009) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 158806 + ... + 162805.

Almost surely, 2^643222000 is an apocalyptic number.

It is an amenable number.

643222000 is an abundant number, since it is smaller than the sum of its proper divisors (912093632).

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

643222000 is a wasteful number, since it uses less digits than its factorization.

643222000 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 321634 (or 321618 counting only the distinct ones).

The product of its (nonzero) digits is 576, while the sum is 19.

The square root of 643222000 is about 25361.8217011318. The cubic root of 643222000 is about 863.2176202189.

Adding to 643222000 its reverse (222346), we get a palindrome (643444346).

The spelling of 643222000 in words is "six hundred forty-three million, two hundred twenty-two thousand".