643492872 has 48 divisors (see below), whose sum is σ = 1901231280. Its totient is φ = 194997600.

The previous prime is 643492853. The next prime is 643492877. The reversal of 643492872 is 278294346.

It is not an unprimeable number, because it can be changed into a prime (643492877) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 405454 + ... + 407037.

It is an arithmetic number, because the mean of its divisors is an integer number (39608985).

Almost surely, 2^643492872 is an apocalyptic number.

It is an amenable number.

643492872 is an abundant number, since it is smaller than the sum of its proper divisors (1257738408).

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

643492872 is a wasteful number, since it uses less digits than its factorization.

643492872 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 812514 (or 812507 counting only the distinct ones).

The product of its digits is 580608, while the sum is 45.

The square root of 643492872 is about 25367.1612917173. The cubic root of 643492872 is about 863.3387752109.

The spelling of 643492872 in words is "six hundred forty-three million, four hundred ninety-two thousand, eight hundred seventy-two".