643615436 has 6 divisors (see below), whose sum is σ = 1126327020. Its totient is φ = 321807716.

The previous prime is 643615409. The next prime is 643615447. The reversal of 643615436 is 634516346.

643615436 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a self number, because there is not a number n which added to its sum of digits gives 643615436.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 80451926 + ... + 80451933.

It is an arithmetic number, because the mean of its divisors is an integer number (187721170).

Almost surely, 2^643615436 is an apocalyptic number.

It is an amenable number.

643615436 is a deficient number, since it is larger than the sum of its proper divisors (482711584).

643615436 is a wasteful number, since it uses less digits than its factorization.

643615436 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 160903863 (or 160903861 counting only the distinct ones).

The product of its digits is 155520, while the sum is 38.

The square root of 643615436 is about 25369.5769771591. The cubic root of 643615436 is about 863.3935841766.

The spelling of 643615436 in words is "six hundred forty-three million, six hundred fifteen thousand, four hundred thirty-six".