6446666646 has 48 divisors (see below), whose sum is σ = 16181871264. Its totient is φ = 1816670592.

The previous prime is 6446666623. The next prime is 6446666651. The reversal of 6446666646 is 6466666446.

It is a Smith number, since the sum of its digits (54) coincides with the sum of the digits of its prime factors.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 6446666592 and 6446666601.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 341241 + ... + 359636.

It is an arithmetic number, because the mean of its divisors is an integer number (337122318).

Almost surely, 2^6446666646 is an apocalyptic number.

6446666646 is an abundant number, since it is smaller than the sum of its proper divisors (9735204618).

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

6446666646 is a wasteful number, since it uses less digits than its factorization.

6446666646 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 700965 (or 700962 counting only the distinct ones).

The product of its digits is 17915904, while the sum is 54.

The square root of 6446666646 is about 80291.1367835828. The cubic root of 6446666646 is about 1861.1372632229.

The spelling of 6446666646 in words is "six billion, four hundred forty-six million, six hundred sixty-six thousand, six hundred forty-six".