643668793 has 8 divisors (see below), whose sum is σ = 647542976. Its totient is φ = 639802800.

The previous prime is 643668749. The next prime is 643668797. The reversal of 643668793 is 397866346.

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

It is a cyclic number.

It is not a de Polignac number, because 643668793 - 2²⁵ = 610114361 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 643668793.

It is not an unprimeable number, because it can be changed into a prime (643668797) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 229228 + ... + 232018.

It is an arithmetic number, because the mean of its divisors is an integer number (80942872).

Almost surely, 2^643668793 is an apocalyptic number.

It is an amenable number.

643668793 is a deficient number, since it is larger than the sum of its proper divisors (3874183).

643668793 is a wasteful number, since it uses less digits than its factorization.

643668793 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4095.

The product of its digits is 3919104, while the sum is 52.

The square root of 643668793 is about 25370.6285495649. The cubic root of 643668793 is about 863.4174425326.

The spelling of 643668793 in words is "six hundred forty-three million, six hundred sixty-eight thousand, seven hundred ninety-three".