643610636 has 12 divisors (see below), whose sum is σ = 1185598680. Its totient is φ = 304868160.

The previous prime is 643610537. The next prime is 643610647. The reversal of 643610636 is 636016346.

It is a junction number, because it is equal to n+sod(n) for n = 643610596 and 643610605.

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, 4234205 + ... + 4234356.

It is an arithmetic number, because the mean of its divisors is an integer number (98799890).

Almost surely, 2^643610636 is an apocalyptic number.

It is an amenable number.

643610636 is a deficient number, since it is larger than the sum of its proper divisors (541988044).

643610636 is a wasteful number, since it uses less digits than its factorization.

643610636 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8468584 (or 8468582 counting only the distinct ones).

The product of its (nonzero) digits is 46656, while the sum is 35.

The square root of 643610636 is about 25369.4823754841. The cubic root of 643610636 is about 863.3914378124.

The spelling of 643610636 in words is "six hundred forty-three million, six hundred ten thousand, six hundred thirty-six".