643845726428 has 12 divisors (see below), whose sum is σ = 1142599458672. Its totient is φ = 317388738240.

The previous prime is 643845726427. The next prime is 643845726481. The reversal of 643845726428 is 824627548346.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (643845726427) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1133530925 + ... + 1133531492.

It is an arithmetic number, because the mean of its divisors is an integer number (95216621556).

Almost surely, 2^643845726428 is an apocalyptic number.

It is an amenable number.

643845726428 is a deficient number, since it is larger than the sum of its proper divisors (498753732244).

643845726428 is a wasteful number, since it uses less digits than its factorization.

643845726428 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2267062492 (or 2267062490 counting only the distinct ones).

The product of its digits is 61931520, while the sum is 59.

The spelling of 643845726428 in words is "six hundred forty-three billion, eight hundred forty-five million, seven hundred twenty-six thousand, four hundred twenty-eight".