643656113612 has 12 divisors (see below), whose sum is σ = 1126416341400. Its totient is φ = 321822873216.

The previous prime is 643656113567. The next prime is 643656113669. The reversal of 643656113612 is 216311656346.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1009478 + ... + 1518669.

It is an arithmetic number, because the mean of its divisors is an integer number (93868028450).

Almost surely, 2^643656113612 is an apocalyptic number.

It is an amenable number.

643656113612 is a deficient number, since it is larger than the sum of its proper divisors (482760227788).

643656113612 is a wasteful number, since it uses less digits than its factorization.

643656113612 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2591800 (or 2591798 counting only the distinct ones).

The product of its digits is 466560, while the sum is 44.

Adding to 643656113612 its reverse (216311656346), we get a palindrome (859967769958).

The spelling of 643656113612 in words is "six hundred forty-three billion, six hundred fifty-six million, one hundred thirteen thousand, six hundred twelve".