643354561863 has 36 divisors (see below), whose sum is σ = 1007596635552. Its totient is φ = 395389537920.

The previous prime is 643354561807. The next prime is 643354561867. The reversal of 643354561863 is 368165453346.

643354561863 is a `hidden beast` number, since 6 + 4 + 3 + 3 + 5 + 456 + 186 + 3 = 666.

It is not a de Polignac number, because 643354561863 - 2⁹ = 643354561351 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (643354561867) by changing a digit.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 879570 + ... + 1435392.

It is an arithmetic number, because the mean of its divisors is an integer number (27988795432).

Almost surely, 2^643354561863 is an apocalyptic number.

643354561863 is a deficient number, since it is larger than the sum of its proper divisors (364242073689).

643354561863 is a wasteful number, since it uses less digits than its factorization.

643354561863 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 556616 (or 556600 counting only the distinct ones).

The product of its digits is 18662400, while the sum is 54.

The spelling of 643354561863 in words is "six hundred forty-three billion, three hundred fifty-four million, five hundred sixty-one thousand, eight hundred sixty-three".