643802327538 has 16 divisors (see below), whose sum is σ = 1287612554976. Its totient is φ = 214599459200.

The previous prime is 643802327507. The next prime is 643802327557. The reversal of 643802327538 is 835723208346.

It is a Smith number, since the sum of its digits (51) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax 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, 1600045 + ... + 1961567.

It is an arithmetic number, because the mean of its divisors is an integer number (80475784686).

Almost surely, 2^643802327538 is an apocalyptic number.

643802327538 is an abundant number, since it is smaller than the sum of its proper divisors (643810227438).

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

643802327538 is a wasteful number, since it uses less digits than its factorization.

643802327538 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 658329.

The product of its (nonzero) digits is 5806080, while the sum is 51.

The spelling of 643802327538 in words is "six hundred forty-three billion, eight hundred two million, three hundred twenty-seven thousand, five hundred thirty-eight".