643523164 has 12 divisors (see below), whose sum is σ = 1175129424. Its totient is φ = 307771904.

The previous prime is 643523149. The next prime is 643523171. The reversal of 643523164 is 461325346.

643523164 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3497317 + ... + 3497500.

It is an arithmetic number, because the mean of its divisors is an integer number (97927452).

Almost surely, 2^643523164 is an apocalyptic number.

It is an amenable number.

643523164 is a deficient number, since it is larger than the sum of its proper divisors (531606260).

643523164 is a wasteful number, since it uses less digits than its factorization.

643523164 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6994844 (or 6994842 counting only the distinct ones).

The product of its digits is 51840, while the sum is 34.

The square root of 643523164 is about 25367.7583558343. The cubic root of 643523164 is about 863.3523220317.

The spelling of 643523164 in words is "six hundred forty-three million, five hundred twenty-three thousand, one hundred sixty-four".