643394026808 has 16 divisors (see below), whose sum is σ = 1299161015880. Its totient is φ = 296951089248.

The previous prime is 643394026777. The next prime is 643394026817. The reversal of 643394026808 is 808620493346.

It is a super-3 number, since 3×643394026808³ (a number of 36 digits) contains 333 as substring.

It is a Smith number, since the sum of its digits (53) coincides with the sum of the digits of its prime factors.

It is a self number, because there is not a number n which added to its sum of digits gives 643394026808.

It is a congruent number.

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, 3093240410 + ... + 3093240617.

Almost surely, 2^643394026808 is an apocalyptic number.

It is an amenable number.

643394026808 is an abundant number, since it is smaller than the sum of its proper divisors (655766989072).

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

643394026808 is a wasteful number, since it uses less digits than its factorization.

643394026808 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6186481046 (or 6186481042 counting only the distinct ones).

The product of its (nonzero) digits is 5971968, while the sum is 53.

The spelling of 643394026808 in words is "six hundred forty-three billion, three hundred ninety-four million, twenty-six thousand, eight hundred eight".