643974795845 has 8 divisors (see below), whose sum is σ = 773041586976. Its totient is φ = 514998615376.

The previous prime is 643974795829. The next prime is 643974796007. The reversal of 643974795845 is 548597479346.

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

It is a cyclic number.

It is not a de Polignac number, because 643974795845 - 2⁴ = 643974795829 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 22637027 + ... + 22665456.

It is an arithmetic number, because the mean of its divisors is an integer number (96630198372).

Almost surely, 2^643974795845 is an apocalyptic number.

It is an amenable number.

643974795845 is a deficient number, since it is larger than the sum of its proper divisors (129066791131).

643974795845 is a wasteful number, since it uses less digits than its factorization.

643974795845 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 45305331.

The product of its digits is 914457600, while the sum is 71.

The spelling of 643974795845 in words is "six hundred forty-three billion, nine hundred seventy-four million, seven hundred ninety-five thousand, eight hundred forty-five".