643844339560 has 16 divisors (see below), whose sum is σ = 1448649764100. Its totient is φ = 257537735808.

The previous prime is 643844339549. The next prime is 643844339573. The reversal of 643844339560 is 65933448346.

It can be written as a sum of positive squares in 2 ways, for example, as 627108777604 + 16735561956 = 791902^2 + 129366^2 .

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 8048054205 + ... + 8048054284.

Almost surely, 2^643844339560 is an apocalyptic number.

It is an amenable number.

643844339560 is an abundant number, since it is smaller than the sum of its proper divisors (804805424540).

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

643844339560 is a wasteful number, since it uses less digits than its factorization.

643844339560 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 16096108500 (or 16096108496 counting only the distinct ones).

The product of its (nonzero) digits is 22394880, while the sum is 55.

The spelling of 643844339560 in words is "six hundred forty-three billion, eight hundred forty-four million, three hundred thirty-nine thousand, five hundred sixty".