643384749 has 48 divisors (see below), whose sum is σ = 1060473600. Its totient is φ = 345292416.

The previous prime is 643384699. The next prime is 643384789. The reversal of 643384749 is 947483346.

643384749 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 643384749 - 2⁹ = 643384237 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 643384698 and 643384707.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (643384789) 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, 155692 + ... + 159770.

It is an arithmetic number, because the mean of its divisors is an integer number (22093200).

Almost surely, 2^643384749 is an apocalyptic number.

It is an amenable number.

643384749 is a deficient number, since it is larger than the sum of its proper divisors (417088851).

643384749 is a wasteful number, since it uses less digits than its factorization.

643384749 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4162 (or 4155 counting only the distinct ones).

The product of its digits is 1741824, while the sum is 48.

The square root of 643384749 is about 25365.0300413778. The cubic root of 643384749 is about 863.2904182872.

The spelling of 643384749 in words is "six hundred forty-three million, three hundred eighty-four thousand, seven hundred forty-nine".