643920694118 has 32 divisors (see below), whose sum is σ = 1047368599200. Its totient is φ = 296900449248.

The previous prime is 643920694097. The next prime is 643920694139. The reversal of 643920694118 is 811496029346.

643920694118 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is an interprime number because it is at equal distance from previous prime (643920694097) and next prime (643920694139).

It is a self number, because there is not a number n which added to its sum of digits gives 643920694118.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 4405580 + ... + 4549392.

It is an arithmetic number, because the mean of its divisors is an integer number (32730268725).

Almost surely, 2^643920694118 is an apocalyptic number.

643920694118 is a deficient number, since it is larger than the sum of its proper divisors (403447905082).

643920694118 is a wasteful number, since it uses less digits than its factorization.

643920694118 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 144873 (or 144847 counting only the distinct ones).

The product of its (nonzero) digits is 2239488, while the sum is 53.

The spelling of 643920694118 in words is "six hundred forty-three billion, nine hundred twenty million, six hundred ninety-four thousand, one hundred eighteen".