643745247516776 has 16 divisors (see below), whose sum is σ = 1207027215867300. Its totient is φ = 321871323285504.

The previous prime is 643745247516719. The next prime is 643745247516797. The reversal of 643745247516776 is 677615742547346.

It can be written as a sum of positive squares in 2 ways, for example, as 607835790514276 + 35909457002500 = 24654326^2 + 5992450^2 .

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, 160453721 + ... + 164416808.

Almost surely, 2^{643745247516776} is an apocalyptic number.

It is an amenable number.

643745247516776 is a deficient number, since it is larger than the sum of its proper divisors (563281968350524).

643745247516776 is a wasteful number, since it uses less digits than its factorization.

643745247516776 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 325118228 (or 325118224 counting only the distinct ones).

The product of its digits is 4978713600, while the sum is 74.

The spelling of 643745247516776 in words is "six hundred forty-three trillion, seven hundred forty-five billion, two hundred forty-seven million, five hundred sixteen thousand, seven hundred seventy-six".