643609968960 has 448 divisors, whose sum is σ = 2391787740672. Its totient is φ = 143586852864.

The previous prime is 643609968923. The next prime is 643609968977. The reversal of 643609968960 is 69869906346.

It is a tau number, because it is divible by the number of its divisors (448).

It is a junction number, because it is equal to n+sod(n) for n = 643609968891 and 643609968900.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 70158934 + ... + 70168106.

Almost surely, 2^643609968960 is an apocalyptic number.

643609968960 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 643609968960, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1195893870336).

643609968960 is an abundant number, since it is smaller than the sum of its proper divisors (1748177771712).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

643609968960 is a wasteful number, since it uses less digits than its factorization.

643609968960 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9450 (or 9440 counting only the distinct ones).

The product of its (nonzero) digits is 90699264, while the sum is 66.

The spelling of 643609968960 in words is "six hundred forty-three billion, six hundred nine million, nine hundred sixty-eight thousand, nine hundred sixty".