643687786346 has 32 divisors (see below), whose sum is σ = 1082837984256. Its totient is φ = 284433184000.

The previous prime is 643687786321. The next prime is 643687786349.

643687786346 is nontrivially palindromic in base 10.

It is not an unprimeable number, because it can be changed into a prime (643687786349) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1016330 + ... + 1523253.

It is an arithmetic number, because the mean of its divisors is an integer number (33838687008).

Almost surely, 2^643687786346 is an apocalyptic number.

643687786346 is a deficient number, since it is larger than the sum of its proper divisors (439150197910).

643687786346 is a wasteful number, since it uses less digits than its factorization.

643687786346 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2539918.

The product of its digits is 585252864, while the sum is 68.

The spelling of 643687786346 in words is "six hundred forty-three billion, six hundred eighty-seven million, seven hundred eighty-six thousand, three hundred forty-six".