643205716 has 24 divisors (see below), whose sum is σ = 1168425216. Its totient is φ = 309594720.

The previous prime is 643205711. The next prime is 643205723. The reversal of 643205716 is 617502346.

It is a happy number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (643205711) 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 7 ways as a sum of consecutive naturals, for example, 16576 + ... + 39511.

It is an arithmetic number, because the mean of its divisors is an integer number (48684384).

Almost surely, 2^643205716 is an apocalyptic number.

It is an amenable number.

643205716 is a deficient number, since it is larger than the sum of its proper divisors (525219500).

643205716 is a wasteful number, since it uses less digits than its factorization.

643205716 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 56199 (or 56197 counting only the distinct ones).

The product of its (nonzero) digits is 30240, while the sum is 34.

The square root of 643205716 is about 25361.5006653786. The cubic root of 643205716 is about 863.2103356658.

The spelling of 643205716 in words is "six hundred forty-three million, two hundred five thousand, seven hundred sixteen".