643786075940 has 48 divisors (see below), whose sum is σ = 1598365440000. Its totient is φ = 213115389312.

The previous prime is 643786075937. The next prime is 643786075949. The reversal of 643786075940 is 49570687346.

It is a self number, because there is not a number n which added to its sum of digits gives 643786075940.

It is not an unprimeable number, because it can be changed into a prime (643786075949) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 79279940 + ... + 79288059.

It is an arithmetic number, because the mean of its divisors is an integer number (33299280000).

Almost surely, 2^643786075940 is an apocalyptic number.

It is an amenable number.

643786075940 is an abundant number, since it is smaller than the sum of its proper divisors (954579364060).

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

643786075940 is a wasteful number, since it uses less digits than its factorization.

643786075940 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 158568044 (or 158568042 counting only the distinct ones).

The product of its (nonzero) digits is 30481920, while the sum is 59.

The spelling of 643786075940 in words is "six hundred forty-three billion, seven hundred eighty-six million, seventy-five thousand, nine hundred forty".