643300660543 has 16 divisors (see below), whose sum is σ = 667221408256. Its totient is φ = 619726010400.

The previous prime is 643300660427. The next prime is 643300660549. The reversal of 643300660543 is 345066003346.

It is a happy number.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-643300660543 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 643300660496 and 643300660505.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (643300660549) by changing a digit.

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 15 ways as a sum of consecutive naturals, for example, 28003180 + ... + 28026142.

It is an arithmetic number, because the mean of its divisors is an integer number (41701338016).

Almost surely, 2^643300660543 is an apocalyptic number.

643300660543 is a deficient number, since it is larger than the sum of its proper divisors (23920747713).

643300660543 is a wasteful number, since it uses less digits than its factorization.

643300660543 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 30454.

The product of its (nonzero) digits is 466560, while the sum is 40.

Adding to 643300660543 its reverse (345066003346), we get a palindrome (988366663889).

The spelling of 643300660543 in words is "six hundred forty-three billion, three hundred million, six hundred sixty thousand, five hundred forty-three".