643000072 has 64 divisors (see below), whose sum is σ = 1437710400. Its totient is φ = 265731840.

The previous prime is 643000067. The next prime is 643000079. The reversal of 643000072 is 270000346.

It is a Harshad number since it is a multiple of its sum of digits (22).

It is not an unprimeable number, because it can be changed into a prime (643000079) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 72454 + ... + 80842.

It is an arithmetic number, because the mean of its divisors is an integer number (22464225).

Almost surely, 2^643000072 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 643000072, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (718855200).

643000072 is an abundant number, since it is smaller than the sum of its proper divisors (794710328).

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

643000072 is a wasteful number, since it uses less digits than its factorization.

643000072 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8486 (or 8482 counting only the distinct ones).

The product of its (nonzero) digits is 1008, while the sum is 22.

The square root of 643000072 is about 25357.4460859133. The cubic root of 643000072 is about 863.1183314318.

The spelling of 643000072 in words is "six hundred forty-three million, seventy-two", and thus it is an aban number.