643005979963 has 24 divisors (see below), whose sum is σ = 685402394864. Its totient is φ = 602463718080.

The previous prime is 643005979949. The next prime is 643005980011. The reversal of 643005979963 is 369979500346.

It is not a de Polignac number, because 643005979963 - 2¹³ = 643005971771 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (643005979933) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 7980145 + ... + 8060317.

Almost surely, 2^643005979963 is an apocalyptic number.

643005979963 is a deficient number, since it is larger than the sum of its proper divisors (42396414901).

643005979963 is an equidigital number, since it uses as much as digits as its factorization.

643005979963 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 80395 (or 80324 counting only the distinct ones).

The product of its (nonzero) digits is 33067440, while the sum is 61.

The spelling of 643005979963 in words is "six hundred forty-three billion, five million, nine hundred seventy-nine thousand, nine hundred sixty-three".