643866565668346 has 8 divisors (see below), whose sum is σ = 999103291554420. Its totient is φ = 310832135150208.

The previous prime is 643866565668187. The next prime is 643866565668367.

643866565668346 is nontrivially palindromic in base 10.

It can be written as a sum of positive squares in 2 ways, for example, as 620490414026025 + 23376151642321 = 24909645^2 + 4834889^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a self number, because there is not a number n which added to its sum of digits gives 643866565668346.

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, 5550573841911 + ... + 5550573842026.

Almost surely, 2^{643866565668346} is an apocalyptic number.

643866565668346 is a deficient number, since it is larger than the sum of its proper divisors (355236725886074).

643866565668346 is a wasteful number, since it uses less digits than its factorization.

643866565668346 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11101147683968.

The product of its digits is 64497254400, while the sum is 82.

The spelling of 643866565668346 in words is "six hundred forty-three trillion, eight hundred sixty-six billion, five hundred sixty-five million, six hundred sixty-eight thousand, three hundred forty-six".