643759960 has 16 divisors (see below), whose sum is σ = 1448460000. Its totient is φ = 257503968.

The previous prime is 643759937. The next prime is 643759973. The reversal of 643759960 is 69957346.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 8046960 + ... + 8047039.

It is an arithmetic number, because the mean of its divisors is an integer number (90528750).

Almost surely, 2^643759960 is an apocalyptic number.

It is an amenable number.

643759960 is an abundant number, since it is smaller than the sum of its proper divisors (804700040).

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

643759960 is a wasteful number, since it uses less digits than its factorization.

643759960 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 16094010 (or 16094006 counting only the distinct ones).

The product of its (nonzero) digits is 1224720, while the sum is 49.

The square root of 643759960 is about 25372.4251895636. The cubic root of 643759960 is about 863.4582044186.

The spelling of 643759960 in words is "six hundred forty-three million, seven hundred fifty-nine thousand, nine hundred sixty".