643773812 has 24 divisors (see below), whose sum is σ = 1257608352. Its totient is φ = 285818400.

The previous prime is 643773803. The next prime is 643773847. The reversal of 643773812 is 218377346.

It is a super-2 number, since 2×643773812² = 828889442034022688, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 643773812.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 168239 + ... + 172022.

It is an arithmetic number, because the mean of its divisors is an integer number (52400348).

Almost surely, 2^643773812 is an apocalyptic number.

It is an amenable number.

643773812 is a deficient number, since it is larger than the sum of its proper divisors (613834540).

643773812 is a wasteful number, since it uses less digits than its factorization.

643773812 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 340319 (or 340317 counting only the distinct ones).

The product of its digits is 169344, while the sum is 41.

The square root of 643773812 is about 25372.6981616067. The cubic root of 643773812 is about 863.4643974812.

The spelling of 643773812 in words is "six hundred forty-three million, seven hundred seventy-three thousand, eight hundred twelve".