646816444 has 12 divisors (see below), whose sum is σ = 1156012704. Its totient is φ = 316527104.

The previous prime is 646816439. The next prime is 646816447. The reversal of 646816444 is 444618646.

646816444 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 646816444.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (646816447) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1720069 + ... + 1720444.

It is an arithmetic number, because the mean of its divisors is an integer number (96334392).

Almost surely, 2^646816444 is an apocalyptic number.

It is an amenable number.

646816444 is a deficient number, since it is larger than the sum of its proper divisors (509196260).

646816444 is a wasteful number, since it uses less digits than its factorization.

646816444 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3440564 (or 3440562 counting only the distinct ones).

The product of its digits is 442368, while the sum is 43.

The square root of 646816444 is about 25432.5862625098. The cubic root of 646816444 is about 864.8225744553.

The spelling of 646816444 in words is "six hundred forty-six million, eight hundred sixteen thousand, four hundred forty-four".