643006706 has 8 divisors (see below), whose sum is σ = 982708524. Its totient is φ = 315437200.

The previous prime is 643006687. The next prime is 643006723. The reversal of 643006706 is 607600346.

It can be written as a sum of positive squares in 2 ways, for example, as 574033681 + 68973025 = 23959^2 + 8305^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a Curzon number.

It is an unprimeable number.

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 3 ways as a sum of consecutive naturals, for example, 3032945 + ... + 3033156.

Almost surely, 2^643006706 is an apocalyptic number.

643006706 is a deficient number, since it is larger than the sum of its proper divisors (339701818).

643006706 is a wasteful number, since it uses less digits than its factorization.

643006706 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6066156.

The product of its (nonzero) digits is 18144, while the sum is 32.

The square root of 643006706 is about 25357.5768952792. The cubic root of 643006706 is about 863.1212997608.

The spelling of 643006706 in words is "six hundred forty-three million, six thousand, seven hundred six".