643808012 has 12 divisors (see below), whose sum is σ = 1138279800. Its totient is φ = 318585216.

The previous prime is 643807993. The next prime is 643808023. The reversal of 643808012 is 210808346.

It is a self number, because there is not a number n which added to its sum of digits gives 643808012.

It is an unprimeable number.

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 3 ways as a sum of consecutive naturals, for example, 829262 + ... + 830037.

It is an arithmetic number, because the mean of its divisors is an integer number (94856650).

Almost surely, 2^643808012 is an apocalyptic number.

It is an amenable number.

643808012 is a deficient number, since it is larger than the sum of its proper divisors (494471788).

643808012 is a wasteful number, since it uses less digits than its factorization.

643808012 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1659400 (or 1659398 counting only the distinct ones).

The product of its (nonzero) digits is 9216, while the sum is 32.

The square root of 643808012 is about 25373.3721054179. The cubic root of 643808012 is about 863.4796875096.

The spelling of 643808012 in words is "six hundred forty-three million, eight hundred eight thousand, twelve".